Car Sharing

WaPo has an interesting group of articles about car sharing. I personally like my car. Because I'm so short, it's difficult to find a car that fits me. Plus, I seem to drive out of day-trip range every weekend. But for people who aren't freaks and who live and work close to public transportation, it sounds like an interesting idea. I have to wonder, though, how often the companies that rent out these cars check on them to see how they're doing. Is there a system inside the car that tells home base that it's nearing time for the 30,000 mile check-up? And how do they determine where to place cars and how many to keep there? Is it based on membership? Is there a minimum number of members who must live within a mile of a parking lot before they'll place a car there? And what if you need a specific vehicle, like a truck for a trip to Home Depot? There are some setups like this in other cities (though D.C. is the only place with more than one company offering the service), so it will be interesting to see how this works out.