[jpollock]

In order to control what happens in the car when you're not in it.

I would expect driverless taxis to end up like public toilets.

[danielbln]

You don't have to register at the toilet with your ID/driver's license. You do however, have to do that when you use e.g car sharing, and the first question the system usually asks you, is: "is the car clean?". If no, then the previous renter will be liable. So this is already a solved problem.

[raldi]

If public toilets had a user reputation system (like Uber), they would be as lovely as the ones in Japan. Unless you had a bad reputation, in which case you deserve what you get.