Aren't cars made during the past 10 years (and moreso 5 years) supposed to have sophisticated "black-box" data logging systems that record a lot of what's going on with the car (steering wheel movements, braking, speed, etc) compared to 10+ years ago?
So much more logging that it's become standard practice for cops to have sophisticated data recovery tools sold to them by third-party equipment makers with slick marketing that tells cops that there's valuable evidence just waiting for them at crash scenes?
If so, then it should be a simple matter to know the state of the ignition switch or airbags prior to, say, loss of main battery bus or engine RPM offscale or zero (the loss of either one being the indicator of impact damage in progress).