Would you be willing to share your car with others when you're not using it?

I asked ZipCar (many times) to let me buy one of their fleet cars. While it was parked at home or work, I'd be thrilled if someone else could use it. I'd only ask that I got priority reservations (commute, errands, day care, etc).

My notion, at scale, would have solved the ZipCar's capital problem. And renting out my fleet car would have offset my own expenses. Win/win.

But no one seemed interested.

(This notion doesn't solve your empty tank problem. That'd piss me off.)