this might help http://www.zcars.org.uk/mini/mini_main.htm
These cars were in an issue of CCC a few months back.. maybe the same ones you've seen? I think they said they'd created their own gearbox to get around the reverse thing.
I've been known to daydream about a turbo hayabusa engine in one of these..
Those engines are insane.. there are people on hayabusa forums running over 500hp!!