Many years ago, 1950's, I think there was a boat that a man drove his van onto and used the rear wheels to drive the prop. It was seen often between Barnes and Putney.
I cant remember the make of van either, and I also saw the boat without van on once,down Putney I think.I remember seeing it during the late 1960s, I sailed from Thamesis at that time, just downstream from Kingston bridge, would have been 1966 to 1968- ish. Cannot remember the make of van though!