Elon Musk explains how Tesla’s Cybercab fleet will work:

“Think of Tesla like some combination of Airbnb and Uber. There’ll be some number of cars that Tesla owns itself and operates in the fleet, and then there’ll be a bunch of cars owned by the end user.

That end user can add or subtract their car from the fleet whenever they want. They can decide if they only want the car to be used by friends and family, by five-star users, or by anyone at any time.

They could have the car come back to them and be exclusively theirs, like an Airbnb. You could rent out your guest room or not anytime you want.”