When I was living in Redhill I got my Passat serviced at a place which I think was in Horley (my memory of the area sucks). It was on a crossroads at traffic lights on the road between Redhill and Gatwick and was joined onto an Audi garage. I can't for the life of me remember the name of the place.
I don't know if that's any help to you but I found their service to be quite good.