Not only that, Tesla will operate their own fleet of self-driving "Uber" cars where demand exceeds the supply of customer-provided cars.
I absolutely love that idea. Honestly, I'd love to have a car for myself, but no way that I could ever afford that in the next 5 years. Living in a city, I can get everywhere with my bike, public transport and carsharing. For the few trips where I need to transport something bigger, I can rent a transporter, no problem, and that's still all much cheaper than buying a car. Seeing it as an investment that is going to pay off reliably might open the gate for less expensive loans if you actually want to get a new car, because the bank can be sure that some amount of money will be made by the car itself.
Why even own the car at that point?
If you want to go on vacation, I guess. And, if the car belongs to you, you can be sure that it will be in your garage in the morning when you need to go somewhere. The option of turning off the sharing aspect and then just have the car for yourself is really nice to think about. Humans like to own things.
Still it does illustrate a point. How feasible is it to not own a car if you need one to go to work every day or grab a gallon of milk from the grocery store?
As Phuncz showed, it only really depends on where you live. I could live my whole life without a car if I stay where I live right now. Riding the bike somewhere is often faster than driving there by car. Even when I go on vacation to somewhere in Europe (where most people get with cars), I can still do that with train and bike if I plan accordingly.
Really, especially in the context of cities, cars should be eliminated wherever possible. If all those people that drove to work everyday for an hour because they're in a traffic jam would just ride with a bike or public transport, there wouldn't be such a thing as traffic jams anymore. The roads would be free for ambulances, fire engines and transporters.
While I'm not sure how feasible Teslas autonomous bus concept is, everything else Elon states as a goal seems quite achievable from their position.