I'm sorry I'm so dense....but those two rates sheets looked like they were shockingly similar in terms of hour/daily and per mile costs. I have plenty of (<50 yo) friends in Philly who don't own a car, or families with children that own zero or one, rather than the standard 2 in the 'burbs. They are pleased with the zipcars. The costs, while less than owning a car (that you use infrequently) is still high enough that they are all motivated to do things like walk/bike/take public more often than they would if they owned a car. I think the 'pay as you go' rather than the 'sunk cost' of an owned car has a powerful psychological effect not unlike home energy monitoring.