I remember seeing in Paris in apartment blocks people had these raised lockers, the idea being you drive your car in so that the bonnet is underneath and you can store stuff above it. I think they were cantilevered off the wall though, they seemed to be "built-in" rather than temporary, can't remember if they had legs or not.
Sorry I can't be more help, I just remember thinking that it was an efficient idea. Where you'd get one is anyone's guess, but how about one of those garden lockers?
SSE