Black boxes have been around for ages. It has been mandatory since 1996 and voluntary prior to that date. The parameters used in the boxes can, if calibrated correctly, show vehicle failures, accident causes and other factors. We expect our airlines to have this technology why not the automobile industry? Peoples fears about abuse by the police and insurance industry are totally unfounded.
If some half baked drunk slammed into your car and tried to blame you, wouldn't you want some evidence to back you up?