I'm extremely curious how "computer vision makes this really easy". Is there a system which can already do that, or are you talking about a hypothetical system where all cars are identical, the camera always has perfect lighting and which can tell vomit apart from a crisp bag on the seat. Having the customer's credit card works only until they do a chargeback, and then you have to go through a long and unpleasant process of proving that yes, it was absolutely, definitely them who made the mess.