I think that, for a lot of people, if they aren't actually driving, the attraction of owning a car vs. merely calling one up shifts quite a bit. If you're driving, the car is an extension of you, and you car more about how it reflects your tastes and personality, so owning is important. But if you're just a passenger, you don't care as much about the kind of car your'e in (most people don't choose taxis based on paint scheme, for example), so I think personal ownership will drop quite a bit once people aren't driving.