I'm a cyclist, never owned a car or driving license, so don't keep up with auto technology..

But I'd think it common sense that all new cars be required to be factory fitted
with front/rear impact resistant mini digital cam recorders
like the after sales kits I mentioned earlier..

[even side cams so all angles are covered ?]

The cams would be auto activated on ignition, and the flash memory cards
auto erasing previously recorded earlier footage, keeping adequate memory capacity constantly available
so that the vital minutes before & after any incident are always preserved.

Same as Cyclist helmet and handlebar cams are becoming increasingly popular and essential.

for instance:

http://www.youtube.com/watch?v=ECs8ZrmH8D8