These golf cart sized green, GHG free, plugin vehicles are being legalized for limited road use all over, almost everywhere people retire.  The local news here just had a feature on them. 

Why not make them rentable with a credit card slot, wirelessly connected to the net.  This could replace how many cars over the next 20 years?  As the technology of batteries increases and safer ultra-light car designs take hold, these could go 50 to 60 mph.

Each rentable car could replace how many cars that are parked 23 hours out of the day?  10 times as many cars people hardly ever drive could be retired for every one of these rentables.

Using a local vehicle coop, a non-profit member owned, non-governmental socialist conspriacy (hehey), a lot of gasoline could be kept from getting guzzled.  The member rental price would be lower, but the general public could still rent by paying a bit more per mile/hour.