For once we went in a car did class R in my Vauhall miriva (no I didn't know the name either until I bought one) its just an anonymous dark diesel front wheel drive tin box. But the thing is that we were not seen by anyone, nobody took a photo, and one marshal asked us I we didn't mind waiting for a moment as there was a road trial going on .. and then he saw the numbers :-)
But it was great fun, my wife enjoyed driving I enjoyed looking at a dry route card and if I run out of motorcycles again I wouldn't mind another car -but it will have to be a diesel they can certainly go up hills, perhaps not FWD though.