It's not exactly solved - your examples are close but not equivalent.

Hotels have many people who work there and cleaners who enter the room daily (no Hendrix hotel a la Altered Carbon yet). Rental cars are secured with your credit card so there's a massive disincentive to trash the vehicle.

Perhaps pervasive recording of the vehicle interior would suffice.

>Rental cars are secured with your credit card so there's a massive disincentive to trash the vehicle.

Yeah, I was thinking along those lines. Trash the vehicle, get a cleaning fee charged to your card.

I think they should record passengers boarding and unboarding, with motorized camera shutters that close while in transit for privacy.

If a human has to clean the car between rides that seems like a pretty big problem

It’s also been solved (or isn’t a problem) with car share apps like Car2Go or Zipcar. Those cars don’t get cleaned between rides, but system asks how clean the car is when you start a trip.