One of the many advantages of living in downtown Toronto is that I have both a ZipCar selection and an Enterprise lot within a couple of blocks of home.  I'll use one or the other for occasional trips to the "edge" of the city (Wal-Mart, other big box stores) which I can group together in a single afternoon.  Otherwise, I have the Queen car right outside my door.  When I factor in the "opportunity cost" of not having $20,000+ tied up in a rapidly-depreciating automobile, the choice is straight-forward.  (I'd estimate that only about 50% of my condo's residents own cars: We have more parking spots than we need.)