I mean, yea. I guess I left out the details of how the car service you were renting from would clean things between uses. Didn't think that was necessary to spell out. There are public 'nap rental' places now that have that particular problem pretty well sorted out.

Think of hotels or airline/train sleeper seats not public transit.

Sleeper trains usually have an attendant in every carriage. Doing that would seem to defeat the point of a self-driving car.

Not necessarily any grosser than a hotel.