The only scenario I'm familiar with in which this could occur is maybe a head-on collision (possibly at an angle). I do hope you were smart enough to wait for the police. Tire marks, traffic cameras, debris at the impact site, lots of things tell the story of a crash.

You should by a dash cam to record everything that happens to use as video proof

witnesses! Hopefully someone so saw it will stand up for you.

Op, I think most cars record their speed if there is an impact. Hopefully, you can get the other asshat's checked.

they can see how fast the car was going before the accident happened pretty easily take it to court challenge it don't out up with bullshit

if you didn't instantly get a witness then you almost should he fault if youre that dumb

Modern cars do have a "black box" that will tell you how fast the prick was going at the exact time of the crash. Assuming it's new enough.