SF regulations (something about requiring the rental be roundtrip vs one-way I think) prevent Car2Go from existing in SF. This is really annoying as it's just sitting there while I have to rush to make sure I do my task in the allotted time I've set then race back to the car's parking spot before time is up.

Zipcar has been quietly asking about this in surveys they give out. My guess is they're probably going to fight car2go if they try to get the regulation overturned and if not, just join them in the same game.