It may have changed but the way we did it: check the value of the car vs the damages. typically anything that needed repairs greater than $1500 would be sold to copart
"Until you run out of idiots. You always run out of idiots eventually." I too thought there there had to be an peak idiot scenario, then I started reading ET.
Sounds like a new niche market - detracer. Remove the various tracking gadgets installed in cars. And phones. And whatever else. One difference between subprime morts and subprime autos is that the models do not expect the price of the asset to increase. While this does not mean there is no bubble, it does suggest any collapse will not be nearly as catastrophic unless demand for used cars just dropped to nearly zilch.