What does your car know about you? We hacked a Chevy to find out.

Behind the wheel, it’s nothing but you, the open road — and your car quietly recording your every move. On a recent drive, a 2017 Chevrolet collected my precise location. It stored my phone’s ID and the people I called. It judged my acceleration and braking style, beaming back reports to its maker General Motors over an always-on Internet connection…