Yes, I knew one in Fishponds. Sorry, I just forgot the name. They do only Mercedes. It's close to that big super market. If you come from the town (Fishponds Road) turn right up in to the London road go over that bridge and then turn left. Then straigh ahead. It looks like a warehouse from out side.
Ah, just found it: Parkway, Parnall Road, Fishponds, BS16 3JQ, 01179656164