Now go make some dollars.

Here is your new business plan:
First you look into how insurance works for zipcar (there are some pretty intense legal and logistical hurdles in this plan), and then you set up a similar infrastructure, but only in pretty urban areas. Your fleet of cars however, will have credit card and cash slots in the front and back seats (like a self checkout at a grocery store), and will be set up like taxis. There will be a system in place wherein anyone who gets in to drive will electronically sign a contract and waivers before the car will start. Once they're going, the person driving will pay a small flat fee based on time in the vehicle, but it will be set up to take fares from the back seat, and subtract that from the fee, so if they get enough fares fast enough, they will turn a profit and the cab will print out a check.