H2 as rolling billboard

[maybe some day...]

Ok, I've seen a few of the pics of the logos on the back windows and the full treatment from the guy with the surf/skate/board shops.
Anyone have any comments on the value to their business from advertising carried/displayed by their H2?
Any anecdotes about clients/business gained (or lost...) from driving an H2 w/ your business emblazoned on it?
Any suggestions for designing a graphics scheme?
Any regrets? I'm a little hesitant to do anything more than the back windows but some of the graphics that I have in mind would be pretty cool if they were bigger.
Any comments on removing vinyl graphics if I find that it is a mistake?