Consider it:

Pre-computer/pre-emissions cars are pretty basic machines. The entire engine in a '60s or '70s-era car, for example, can typically be rebuilt to as-new condition for about $2,000. Or less. And it's a task that can be handled by an Average Joe backyard mechanic type. No special skills or training are needed.

The fuel system in a car of the '60s or '70s consists of a simple, easy-to-rebuild mechanical device - the carburetor - an equally simple fuel pump, some steel lines and a gas tank. Even if you were to replace every single component with a brand-new/reproduction part, the total cost would be in the neighborhood of $1,500 or so. And again, the work is fairly simple and can be handled by an Average Joe, given some patience and a shop manual.

The transmission in an older car can be rebuilt/replaced for less than $1,000. It, too, is a basic device.

The "electronics package" in a '60s or '70s-era car typically consists of an AM/FM radio (perhaps with a tape deck or CB and maybe four speakers) and a basic wiring harness - which can be easily and inexpensively replaced, if need be. There is no ECM, no ABS, ESP or TCS. No wheelspeed sensors, "drive by wire" throttle or microprocessor-controlled "climate control" AC.

A backyard mechanic with some basic tools can can keep such a car running almost indefinitely. Necessary parts are generally easy to get and fairly cheap, too.

A modern car, on the other hand, is a highly complex system of integrated components orders of magnitude more complex than the typical old classic. Anything beyond the most basic routine maintenance is already beyond the ken of most Average Joe, do-it-yourself types. The skill/knowledge and equipment necessary to competently diagnose and repair a modern OBD-equipped car is driving the "backyard mechanic" into the history books.

What will it be like when such cars are 20 or 30 years old?

Remember, most old car hobbyists are self-taught tinkerer types - not professionally trained "technicians" with several thousand dollars' worth of specialized tools and equipment at their disposal.

It's one thing to figure out how a Holley four barrel works - and learn, using books and trial-and-error, to disassemble one and put it back together competently.

It's a whole different ball game to tear into a modern car's digital multi-point EFI system. A few self-taught types might be able to get there; the average DIY hobbyists probably won't make the cut.

Then he'll have to pay someone else - and that gets into money. And paying someone to fix your car defeats the point of being a car hobbyist.

But complexity aside, it's the economics of it all that will likely be the nail in the coffin.

Even today, it is not at all uncommon for a late-model car that has a sound body and a basically sound drivetrain to become uneconomic to repair. For example, replacing the driver/passenger-side SRS/air bag system on a 10-year-old, 150,000 mile Corolla - a car that's worth perhaps $3,500. Replacing the air bags is a $2,000 job. Hello, crusher.

Imagine the cost of rehabbing/replacing just the fuel injection system and its related components, including the wiring harness, ECU and emissions gear, on a 2007 model vehicle (any 2007 model year vehicle) in the year 2037. The cost will likely be absolutely prohibitive - assuming parts are even available. (This gets into a Catch-22; if the parts are very expensive, few people will buy them. If few people buy them, there's little incentive for the aftermarket to produce them.)

The problem is already manifesting itself. For example, owners of mid-'80s era Corvettes with Tuned Port Injection (TPI) are having difficulty locating parts - and the parts, when they're even available, are often massively expensive - on the order of $3,000 dollars for a complete TPI set-up (or aftermarket-equivalent replacement).

And that is just the tip of the proverbial iceberg.

What about new/replacement catalytic converters? (The Corvette and many other late-model cars needs at least two - sometimes as many as four, depending on the model of car.) The EGR system and its related hardware and plumbing? The MAP/MAF/TPS, wheel speed and coolant temperature sensor(s) and their related plumbing? The multiple O2 sensors? Then there's the ABS system, including its sensors and controller, plus the ABS pump. The electronic traction control, the stability control system, the computer-controlled "lock-up" transmission, the electronically controlled climate control, the GPS, the onboard "entertainment system," ECU itself - and the hydra of multiplexed wiring that connects it all together? 2007 model cars also typically have at least four air bags; some as many as six or seven.

Who wants to even think about messing with that - today? Just imagine wading into a worn out "modern" car a quarter-century down the road. Would you wish that job on your worst enemy?

Modern cars are wonderful machines that run better, longer and with less fuss than any of their forbears.

But they are also disposable machines that will likely not be feasible for the average person to keep running or restore once they've reached the outer limits of their service life - and begin to require comprehensive replacement/restoration of their major parts and systems.

There may and probably will be a few well-preserved "originals" in the hands of collectors. But the hobby of working on and restoring cars will become one of working on and restoring older, pre-emissions/pre-computers cars built before the early 1980s.

At least, for the average person.

Late model "classics" will either be too expensive - or just too much hassle.

Here's a sampling:

General Motors currently employs around 5,700 workers in the state of Indiana. Want to guess how many retired GM workers there are in Indiana? More than 90,000 of them - all of them drawing benefits.

You do the math.

Now multiply it several-fold to include similarly stilted in-flow/out-flow numbers in other states where GM has a lot of past (and ever fewer) current employees, such as Michigan.

Like Social Security, the numbers are forbidding: An ever-smaller pool of active workers are having to support an ever-growing pool of ex-workers collecting bennies. But while Uncle Sam can raise Social Security "contributions" levied on active workers to finance benefits for today's retirees, GM can only do one of two things.

The first is cut down on current payroll costs - which it does in part by shuttering operations in North America while opening manufacturing facilities in lower-wage countries such as Mexico and China. Not only does this reduce direct payroll costs, it reduces future "legacy costs" - since the non-union workers in places like China and Mexico don't get $40 per hour or a UAW-guaranteed health/pension package. It also makes it possible for GM to make a little more money per car - and thus, to remain competitive with import brands that don't have the Albatross of billions in legacy costs hanging around their necks.

It's ironic that one of the big drivers of outsourcing is not so much corporate greed as it is corporate necessity. The UAW may not like to hear this, but the truth of the matter is that the plush bennies negotiated by the unions have helped to shutter American manufacturing and sent tens of thousands of American workers to the unemployment line while their jobs are sent overseas.

Yes, NAFTA, GATT and other so-called "free trade" policies played a role. But the bottom line is what it is.

Of course, the unions adamantly refuse to see this - and continue pushing for ever-more-bennies for ever-fewer U.S. workers. Even though the goose that lays the golden eggs is already half-choked to death anyhow. But instead of relaxing the grip around its neck just a little bit, the unions just squeeze all the harder.

The other thing GM and other automakers can do - and have done - is eat the approximately $1,500 per car in legacy costs by "selling" cars either at a loss or at a competitive disadvantage relative to import equivalents. The obvious problem with that, of course, is you can't make money by giving away your product - or by selling it at a return so low the competition is earning considerably more on each sale of its equivalent product. Not indefinitely, anyhow - and certainly not when (unlike, say, Wal-Mart) your share of the market is in decline.

While Toyota accumulates a huge pile of reserve cash, GM (and Ford and Chrysler too) are barely making ends meet. This is bad news today - but it's even worse news as far as tomorrow is concerned, too.

Why?

Because when you're running this lean, there's not a hell of a lot left over for R&D into new technologies, engine designs, car models/types. This is one reason why the Japanese are more "innovative" than American car companies have been in recent years - for example, bringing hybrids to market years before any American automaker did. Toyota and Honda had the money to invest in hybrid development; GM and Ford didn't.

The imports are also better positioned to revise and update existing models more often than American car companies can - another tremendous competitive advantage in a marketplace that demands the newest and latest, soonest.

A third option is to simply fold legacy costs into the sticker prices of new cars - and try to make the customer pay for retiree health and pension benefits.

But customers can elect not to pay by not buying the more expensive U.S.-branded vehicle - so that's not going to work, either.

The reality is this: GM and Ford and Chrysler must find some way to sell their cars at competitive prices relative to the imports - and they must make equivalent money on these sales.

If legacy costs - and obstreperous unions - won't permit this, the American automobile industry will very probably cease to exist within the next 5-10 years.

Here's a list of particulars - the to do's (and not-to-do's):

* Maintaining lane discipline

All this means is using the left lane to pass - and when you're driving faster than the traffic around you. Otherwise, stay in the middle or right lane - and always yield to traffic that's moving faster than you are, even if you're doing the speed limit. It's true the car driving above the limit may be breaking the law - but if you're impeding the flow of traffic, so are you. Besides, it's not your job to enforce the speed limit - and by allowing cars that want to go faster to get by, you'll defuse tension (yours and theirs) as well as contribute to a smoother (and therefore, safer) flow of traffic.

* Look left, then right - and then look left again

More than a few accidents that didn't have to happen happen because a driver pulling out into traffic didn't look left again before making his move. In the time it takes to make the first left-right scan, a car (or motorcycle) may have (and often does) appear "out of nowhere" coming from the driver's left. That's why it pays to look left again - just in case - before you proceed forward.

* Headlights on if it's raining

Visibility is key to avoiding accidents. When it's raining, especially. If your car doesn't have automatic headlights, a good rule to follow is to turn them on whenever it starts to rain. In some states, it's the law - but it's common sense everywhere. Also: Don't be chintzy with the wipers. Use them. That's what they're their for. And reduce your speed. That should go without saying. Not only is visibility lower, stopping distances increase and tire grip decreases on wet surfaces - even if you have all-wheel-drive or four-wheel-drive.

* Watch the yellow line - and stay on your side of it

It's a common sight to see the car ahead wandering across the double yellow - either because the driver's too busy talking on his cell phone, trying to get something out of the glovebox - or is just plain old addled. On country roads with blind corners, this can lead to disastrous accidents - especially when motorcycles are coming the other way. And even if it's just sheetmetal that gets mangled, it's something that didn't have to happen. An accident, properly defined, is something that was pretty much unavoidable. Allowing your car to wander across the double yellow and into the path of other cars isn't.

* Think about stopping before you need to

If you anticipate the need to slow down - and begin to do so early - you'll not only save money by decreasing wear and tear on your brake pads/shoes, you'll be better able to control your car - and keep your passengers comfortable. Just pay attention to the ebb and flow of traffic ahead; when you see the cars way up there beginning to slow, you can gradually lower your speed without having to jam on the brakes. In city/suburban traffic, watch how traffic lights are sequenced. It's often possible to pace yourself so that you either make it through all or most of the lights without having to speed up/slow down (which also wastes fuel) or, if you need to stop for a red, you've got plenty of time to do so gradually - and thus, more safely.

* Look before you back up

Many new cars (and especially, large SUVs) are coming with back-up cameras, but that doesn't mean you can forget about checking your six the good old-fashioned way. To lower your risk of fender-benders (or worse, actually running someone over), scan your mirrors before you touch the shift lever. Then - with your foot on the brake - put the transmission in reverse, so your back-up lights come on and give people nearby a visual cue as to your intentions. Now scan the mirrors again - and if the area behind the vehicle (and to the sides) is clear, slowly begin to back up.

The key here is slowly. No "Rockfords" out of the parking lot. Even if the coast seemed clear, by moving slowly and deliberately, you'll give people and animals you might have missed ample time to get out of the way - and if you do bump into something, the impact is less likely to be catastrophic.

And finally - the Big One:

* Avoid driving tired - or angry

By law, over-the-road truckers may only drive so many hours in a row without time off/sleep. There are no such laws for ordinary motorists - who by and large haven't got anything approaching the skill or experience or judgment of an experienced OTR trucker.

But just because it's not illegal to drive 12 hours straight with only pee and gas stops doesn't mean it's smart. We all have different levels of endurance before our reaction times and perceptions begin to suffer; know yours - and drive within your own limits.

Better to take two days to make a trip than spend eternity in a box six feet under. For the same reason, don't drive when you're furious. It's in just such a state that you're prone to a lapse in judgment you might live to regret.

Or maybe not.

Or (for our sheetmetal eye candy) an engine that's suddenly been outgunned by the latest competitors.

Either way, the pace of change is swift. Yesterday's star is often tomorrow's also-ran.

Nissan's 350Z is one of the few cars of its type to remain consistently appealing, even though the current model's not much different from last year's. Or the year before, for that matter.

Yes, there's a slight uptick in rated output. The 3.5 liter DOHC V-6 now delivers 306 horsepower (vs. 300 previously). There's also a new "power bulge" hood, too. Side impact air bags are now standard - and Bluetooth wireless is available. For hard-core enthusiasts, there's a NISMO package that adds a body kit (lower front and rear fascias, side skirts, underbody air diffuser and rear wing) along with upgraded brakes, track-tuned suspension calibrations, a more aggressive-sounding exhaust system and unique-to-this-model gunmetal gray RAYS super-lightweight forged alloy rims.

But even with these tweaks, today's Z-car is still very much the same as yesterday's Z-car.

Which is why it's still such a contender.

The car is perpetually fun to drive - as well as easy to drive (unlike, say, the peaky and high-strung Honda S2000). Its engine has horsepower on top and torque down low, so it works equally well with either the standard six-speed manual or the optional five-speed automatic. It is capable of decent fuel efficiency, too - close to 30 mpg on the highway and (more significantly) 20 mpg around town. Compare that with the SUV-like mid-teens around-town of the Ford Mustang GT.

Pedal to the metal or just putting along, the 350Z is an exceptionally agreeable companion.

Though quick (0-60 in 5.6-5.8 seconds) and fast (140-plus on top) the Z-car doesn't stake its claim on horsepower alone. The big V-8 in the Mustang GT pulls more strongly, but Ford's pony car can't match the Z-Car's yin-yang handling and reflexes. Corvette will beat it - but costs almost $20,000 more. BMW's Z4 and Mazda's RX-8 are formidable corner carvers, but their styling is love it - or leave it. Meanwhile, the shape Nissan introduced back '03 has held up well. It still looks current and (more important) ought to look just as good in another five years, too. Ten, even.

How many late-model cars can you say that about?

Another thing to like about the 350Z is the driver (and passenger) friendly layout - especially relative to other two-seaters out there.

The Pontiac Solstice/Saturn Sky, for instance, are absolutely gorgeous cars - on the outside. But on the inside, they're nightmares - from virtually impossible to reach switchgear for the power windows to the hard-to-read instruments buried deep in the dashboard to total absence of useful/usable storage cubbies, even for very small things like loose change or an iPod. (Then there's the issue of borderline cheap materials in both these cars - and the shockingly poor sealing of the convertible top and ridiculous levels of wind/road noise intrusion into the cabin.)

The Nissan doesn't depend on the latest electronic gadgets to distinguish itself from the pack, either.

No "mouse inputs" or "menus" to deal with. You want to turn on the AC? Push a button. Turn the temperature up or adjust the fan speed? Turn a knob. It can all be done without taking your eyes off the road - and you'll never fee like putting your fist through the dash.

The 350Z is one of the increasingly rare high-powered sports cars that doesn't require fumbling through the owner's manual to understand how basic controls work - because everthing's obvious and self-explanatory.

Big 8,000 RPM analog tach in the center of things; speedo off to its right - with three smaller gauges for lesser essentials canted toward the driver on top of the center stack. Meaty three-spoke steering wheel with just a few easy-to-comprehend secondary controls for things like stereo volume/channel. A handy (and decent sized) storage cubby right there above the audio system. Rotary knobs to adjust the seats (electric assist is available for those who want that). Short-throw shifter that perfectly fits your hand.

The whole ball of wax unencumbered by the unfortunate kudzu of over-elaborate techno-excess that is making cars from BMW, Lexus and some others as exasperating to drive as they are capable.

Its layout is direct and focused and very much in keeping with the idea that animated the original '70 240-Z. It's a driver's car; not a yupped-up showcase for stuff that's not really relevant to the task at hand. Sharp-looking, too - with a sport bike "pod" theme for the main gauge cluster that tilts with the steering wheel that adds a unique (and functional) touch to the car's racy personality.

The reason the early Z-car made such a great impression and lasted as long as it did was its "legs" - the basic greatness of the design. The same can be said of the current-generation 350Z, which, like its esteemed forbear, should continue to put as big a smile on its owner's face tomorrow as it does today.

Or another five years from now, for that matter.

Is it the "latest thing"? Well, no. But sometimes new isn't necessary an improvement.

Buyer's note: Nissan reportedly will be bringing out an all-new, "next generation" Z-car for 2009, perhaps in spring/summer 2008. It may - or may not be - an improvement over the current car, depending on what you're looking for.

Some Z-Car fans, for example, were unhappy when the original two-seat 240-Z morphed into the two-plus-two 260-Z. And from there evolved into the ever-more-glitzy (unkind souls might say "DiscoDanny") 280-Z, then became the getting-pricey 300ZX - before returning to its no-bullshit 240-Z roots in the form of the current car.

It's hard to know what Nissan has in mind for 2007, so if you like the original and see in this latter-day descendant a kindred soul, now's the time to think seriously about cutting a check.

Come '09, it may be too late.

GM stopped making its EV1 battery-powered coupe because even with subsidies, the retail cost per car was comparable to what you'd pay for something like a BMW 330i luxury-sport sedan. And rather than a powerful, fun-to-drive BMW, your $30,000-something would get you a minimalist two-seater with a range of about 100 miles under absolutely ideal conditions that needed several hours (or longer) to recharge itself.

A modern 250 cc motorcycle is faster, runs longer and costs less than $5,000 brand-new. A decent late-model econobox that gets 35-40 mpg costs less than $15,000.

Not surprisingly, GM gave up and stopped building its electric car - as did all the other big-league automakers.

But for the dedicated -- and deep-pocketed -- electric cars are still available. For example, if you have $108,000 laying around, you could order the Hammacher Schlemmer electric car, straight from the company's latest catalog (for "personalized service,"call 1-800-227-3528 and ask for item number CP-10954).

Unlike the slow-pokey EV1, this one's actually pretty quick - capable of zipping from zero to 60 mph in 4 seconds, according to the brochure. That's within a few tenths of the rear bumper of a new Corvette. The car tops out at 120 mph - all courtesy of more than 1,000 pounds of batteries and DC electric motors under its floor. And because it's only 39 inches wide - about the same as most motorcycles - it can "lane split" like a bike, too (in states where that's allowed).

Driver and passenger sit front-to-back, not side-by-side. The slimline arrangement also makes the car a snap to park.

There's just that $108k price to deal with...

Maybe this is just a rich man's plaything. But the Hammacher Schlemmer electric car gives us an idea of the real-world (i.e., non-subsidized) cost of going gas-less. The Tesla electric sports car (based on the current Lotus) is also a six-figure machine.

It's beautiful, it's fast... but $100k?

Even mass-produced - and even assuming a world of $4 per gallon fuel - it will be a challenge to design and produce an electric vehicle that's cost-competitive with an equivalent gas-powered car. (Or gas-electric hybrid.)

Saving the planet - and saying good-bye to OPEC and fractious Middle Eastern politics - will not be a cheap date.

Unless, of course, someone invents a low-cost/high-energy battery pack. The Hammacher Schlemmer car (and most electric cars) still use 100-year-old technology lead-acid batteries. They are relatively cheap to make - compared with the current alternatives, anyhow - but don't pack much of a punch beyond short-term bursts. This is why a battery is great for starting your car's gas engine - but not so good for keeping it running. The Hammacher Schlemmer runabout, for example, has a best case range of 40-80 miles, depending on conditions. That means if it's cold outside (electric batteries suffer as the temperature drops) or if you hammer it, your "real world range" will probably be less than 50 miles.

Three gallons of unleaded will get you that far - even in a "gas pig" that only returns about 15 mpg. Even at $5 per gallon, it's clear which alternative makes the most sense - economically speaking, anyhow.

And environmentalist critics have pointed out that lead acid batteries are made of two very environmentally unpleasant things - lead and acid. The disposal/hazardous materials issues that would come up if 1,000 pound lead-acid battery packs were ever mass produced are another real obstacle to the practical - and planet-friendly -- electric car.

What we really need is an inexpensive, non-noxious source of electricity. But in the US, we get our jolts and volts primarily from coal-fired and nuclear generating plants. Nuclear power generation gives a lot us the willies - despite all kinds of precautions and a safety record many times better than coal - so we've put the kibosh on new construction. The coal-fed plants, meanwhile, may not be radioactive - but they do spew the majority of the bad stuff that creates air quality problems (including "greenhouse" gasses). More electrical demand means more belching smokestacks.

This is why critics have dismissed so-called "zero emissions" electric cars as "elsewhere emissions" cars.

Back to square one.

Unless you happen to have an extra hundred grand burning a hole in your pocket.

The '08 5-Series, for example, is without question the most powerful (and quickest/fastest) regular production 5-Series sedan BMW has ever offered. For the new model year, it has been updated with a larger, 3-liter, 230 horsepower version of the famous DOHC in-line six now standard in the base 528i ($44,300) and a new-for-2008 twin-turbo version of the 3 liter six that produces 300 horsepower in the mid-range 535i ($49,400). The top 5-Series engine is a 4.8 liter, 360 horsepower V-8 in the 550i ($58,500) that delivers 0-60 runs in the 5.5-5.6 second range.

All three engines are formidable performers that seem to enjoy being run hard -- especially the two in-line sixes. And the new twin-turbo version of the 3-liter engine delivers the level of output and acceleration capability you used to have to upgrade to an M-spec BMW to get. You can still get a manual transmission with the V-8, too. Virtually all the other so-called "sport sedans" these days are automatic-only deals. And the few that aren't (for example, the Nissan Altima) don't have the BMW's upmarket cachet - or the eight cylinders. Wagon versions are available as well.

The rest of the 5-Series' driveline and chassis is equally commendable. Whether you choose the hammer down, throttle oversteer and burnout-friendly hooliganism of the rear-drive 528i, 535i or 550i - or the more responsible power delivery of the AWD-equipped 528xi ($46,500) and 535xi ($51,600), there are few cars with four doors that can match the Beemer's yin-yang balance of track-ready handling precision and right-now responsiveness with a ride that's supple yet not overly firm. To drive a BMW is to forever look down upon lesser machines.

Ok, now for the ugly stuff.

Much has already been written about BMW's notorious iDrive system, which uses a mouse-like button on the center console to access and (in theory) operate various functions, such as the GPS, audio and climate control. To say it's exasperating and needlessly complicated would be unfair. Not to BMW - to the prospective buyer. Because that's soft-pedaling it.

The system is fussy, a challenge to navigate through even when the car's not moving - and is the equivalent, in terms of how it affects the overall driving experience, of finding a curly pube floating in your otherwise 5 Star serving of snapper soup.

BMW has, at least, "simplified" the layout for '08 by incorporating redundant secondary controls of the old-fashioned (and easy to use) rotary knob type for a few essentials like adjusting the temperature of the AC/heater and fan speed - as well as a few pre-programmable Memory functions. But to use the GPS -- or manipulate the stereo system - you'll still have to wade through the iDrive.

They say you get used to it - but that doesn't make it any better. Be absolutely sure you can live with iDrive - before you drive the car home.

Another area of pointless techno-creep is the "e-shifter" for automatic-equipped models. Instead of the usual console-mounted handle you move from Park to Drive, you now have what amounts to an IKEA-looking electric toggle switch - including a button on the top to engage the parking brake. No more manual lever to pull and release - which is probably fine - until the warranty runs out, the electric circuitry and actuators fails and you're faced with a non-working parking brake - and a big repair bill.

But the underlying question is, why is any of this necessary? Or even helpful? What is wrong with a mechanical parking brake lever? It is simple, reliable, does the job perfectly well - and requires no elaborate components that will be more prone to fail and cost you money and hassle down the road. And the e-shifter? You have to tap the toggle just so to get Reverse instead of Neutral - or Drive instead of Reverse. Worse, it gives you no tactile sensation you've moved from one gear/range to another. To know for sure where you are, you must watch the little digital lights illuminate. Like the iDrive controller, the thing merely duplicates a function more efficiently handled by a simpler, less hassle-prone device. There's no good reason for it - or for iDrive - other than to demonstrate that there are more complicated and expensive ways of doing things.

But more complicated and expensive is not necessarily an improvement. Especially when the car involved is built for the person who enjoys the experience of driving - not being thrice-removed from it via over-smart gizmos that pre-empt and usurp him.

These defects inflict more psychic pain than an ugly, extruded plastic GM interior (what were you expecting?) since the rest of the car is so damn good. It's like dating a supermodel who also happens to have a really grating helium voice - or suffering an insolent waiter at your favorite restaurant.

Happily, you can dodge the e-shifter by sticking with the six-speed manual transmission - which makes the car a to more fun to drive anyhow. And if you have to have the Steptronic six-speed automatic, there's still some hope. BMW has added a Sport version of its six-speed automatic (available on the 535i and V-8 550i) which includes steering wheel-mounted paddle shifters that let you avoid the numb-feeling e-shifter on the console.

Unfortunately, there's no getting around iDrive - if you want an '08 5-Series, anyhow. The system is standard - and unavoidable - in all models, from base 528s through the top-of-the-line V-8 540i.

It's sad BMW continues to try to force acceptance of its not-great-idea rather than admit the mistake and redesign the interface to be usable without having to "scroll through menus" or risk crumpling the sheetmetal or having a stroke triggered by sheer exasperation.

Especially since the cars so hobbled are otherwise so appealing.

The production 1954 300SL (W198) was a road-going version of the purpose-built race car (W194) Mercedes-Benz fielded beginning in 1952); it was both a stunner as well as a runner - racking up an impressive series of victories in the Carrera Panamericana road race, the Mille Miglia (with Stirling Moss driving), the 24 hours of Le Mans and the Bern Grand Prix, among other highlights. Max Hoffman, Mercedes' U.S. importer, is credited with convincing company managers to offer a street legal version of the race cars to the buying public - and thus was born the '54-'57 Gullwing coupe.

The unusual design feature which defined these cars was no gimmick, either. Rather, the upward-raising doors were necessitated by the car's underlying tubular steel space frame - which was built up much higher toward the beltline than in a conventional stamped/welded steel perimeter frame. The design conferred tremendous rigidity, but conventional doors could not be fitted without cutting into the tubes - and compromising the whole structure. Engineers came up with the gullwing doors as the solution - a design as functional as it was beautiful.

The only downside was that getting into and out of the car was sometimes challenging - but the engineers were more concerned with how the car performed at speed, less with its parking lot manners.

Most of the SL's bodywork was stamped steel, but aluminum was used for the hood, trunk lid and some exterior skins. Customers could special order a super-lightweight  bodyshell crafted entirely of aluminum - but few did, and the handful that were built have become even more desirable as collectibles. In addition to its tubular frame and signature gullwing doors, the 300SL coupe was powered by a 3-liter in-line six with mechanical fuel injection that delivered 215-hp at 5,800 RPM. Redline was 6,600 RPM.

With the right gearing, the streamlined, lightweight car was capable of exceeding 150 mph - an impressive posting even by modern standards. The straight six was itself a work of art to behold - from  its swoopy aluminum manifold runners to the unusual 45 degree tilt of the block (this was necessary to clear the low-profile hood). The canted position of the engine had another functional benefit as well - putting the car's mass and center of gravity down low and almost exactly in the middle of the car.

Importer Max Hoffman brought approximately 1,100 of the 1,400 initial crop of Gullwing coupes produced to the United States - where they quickly became something of a sensation, even though few aspirants could hope to own one. Unless tthey happened to be movie stars like Clark Gabel, who ordered one. With a base price of more than $11,000 - roughly twice the price of a Cadillac Eldorado - Gullwings were almost as unobtainable then as they have become today.

The less expensive and more prolific 190SL (chassis W121) also appeared on U.S. roads during this time. It was a much more conventional (and thus, affordable) design - no gullwing doors and a smaller, 1.9 liter, 120-hp (carbureted) four cylinder engine - but it retained much of the glamour of the 300SL and sold remarkably well. It was this car, in fact, that probably assured the continued existence of the entire SL line - making a strong business case for itself as much as the Gullwing tugged at one's heartstrings.

The 300SL roadster (W198 II) appeared a few years later, in 1957; it was likewise oriented toward a more practical perspective. The roadster featured a bigger trunk - and most noticeably, easier access, since it had "normal" outward-opening doors. (The tubular steel spaceframe of the Gullwing was still used, but it was modified to accommodate standard doors.) The300SL roadster also boasted improved, four-wheel-disc brakes -- replacing the oversized finned drums used in the Gullwing. Power was up a bit, too - reaching 235-hp, courtesy of higher compression pistons and revised camshaft profiles.

Between 1955 and 1963 (when production of the early SLs ceased) approximately 25,881 190SLs had been built; the more exotic 300SL roadster was produced in much smaller numbers; appx. 1,858 were sold.

But it was clear the future looked bright ahead - and that there would be more SLs to come. The next generation SL (chassis W113) was unveiled at the 1963 Geneva Motor Show.  This car - the 230SL - was at first glance an evolutionary design of the outgoing 190, with much of its styling cues similar to that model. However, there were many significant refinements, including a larger, more powerful (150-hp) 2.3 liter SOHC six-cylinder engine, horizontally "stacked" headlights, and an unusual removable hardtop roof that was lower in the center than at the edges - which earned the car the nickname, "pagoda roof" because of its similarity to oriental temples. In many ways, the 230SL combined the best qualities of the previous 300SL and 190SL into a more user-friendly package that was both elegant and yet still a potent performer.

In 1967, an updated 250SL bowed; the straight six now displaced 2.5 liters and power increased by 20-hp to 170. Bosch mechanical fuel injection was standard, as were four-wheel-disc brakes. As in previous SLs, a 4-speed ZF manual was the standard gearbox -- but in an interesting departure from sporty car practice, an automatic was available and would quickly become a popular feature.

Further improvements came in 1968, when the last of the "pagoda113s" appeared in the form of the 280SL.

Other than its larger engine (now displacing 2.8 liters), slightly revised steering and other small changes, the 280SLs were mostly carryover models. They ran through '71, when production of the "second generation" SLs culminated with approximately 48,912 examples having been built.

By this time, SLs had become fixtures in well-heeled neighborhoods; totems of genteel affluence and good taste - in contrast to the increasingly over-the-top strutting machismo of Italian exotics.  They were also superbly well-put-together by precision obsessed workers - in contrast to the pretty but unreliable Jags of the era.

A major change in direction came in '71 with the unveiling of the all-new "third generation" cars - led by the new (W107) 350SL. Though it still carried the "sport" and light" badging, the 350SL was a departure in theme for the SL-series. With a curb weight in excess of 3,000-lbs., it was more a beefy GT than a trim and lithe sports car, as its ancestors had been.

The new SOHC V-8 (in 3.5 and, later, 4.5 liter displacements) under the hood was further evidence of the change in philosophy - as was the S-Class-derived chassis, which was tuned increasingly for boulevard comfort.

Hard and soft-top versions were available, as before - with the "pagoda" theme carried over to models with the hardtop. These SLs were effective triple-digit tourers, with top speeds of nearly 130 mph (with the larger 4.5 liter engine). However, the energy crunch of the early '70s hit Mercedes just as it did other automakers and by the '74 model year, a less thirsty 2.8 liter six was re-introduced as an option for the efficiency conscious.

Benz would stick with the basic layout of the W107 through the late 1980s, up to the 1989-1990 model year -- making this the longest-serving SL generation (18 years, in total). Approximately 237,287 cars were produced over that time.

Mercedes would continue the line with the subsequent 500 SL roadster (and the later, V-12 powered SL600), updated and massaged versions of which remain in production today. But arguably, the truest inheritor of the legacy of the '54 300SL and the original 190 SL appeared in 1996 - when Mercedes brought out the two-seat, retractable hardtop SLK230. Unlike its big-bruiser, modern-day SL stablemates - none of which could fairly be described as either lightweight or particularly compact -- the SLK was those things in spades. It also had retro Benz styling flourishes, such as the familiar speed bullets on the hood, pontoon fenders, low-slung posture - and road manners more in tune with its early ancestors. This car remains in production as of this writing -- as do the larger SL roadsters

While the SL family tree has bifurcated somewhat in the 50-plus years since the original 300SL and 190SL, all these cars share the genes of an ancestor that has rightly been identified as one of the most significant cars ever built. 

The '54-57 Gullwing coupe.