Supposing we have robot cars in a few decades, it wouldn't be unimaginable to think of a family getting a robot car for their own routine use on a commute, then hooking it up to the new Uber-R robo-car pickup network with a snazzy piece of software. Then it could be used on the network while the family is away on vacations, or asleep at night, or whatever.
Why send a car ahead (wasting lots of energy on moving it) when simply getting an identical one when getting out of the plane should be much cheaper?
I mean, you pay $X for getting that car, and you get $X minus a fee percentage for your own car that gets rented for the same time. And you can get a much different kind (or number) of vehicles than you have at home, which would suit the vacation needs.
