1. everyone should get a dashcam if you don't have one.
2. if you get in an accident, make sure to take pictures or video of everything. their plate, both cars, them, and especially their ID. if they promise to pay, then they should have no problem giving your their ID.

when I get in an accident, I step out of the car with my phone held as if I'm not doing anything but the video is rolling the whole time.