x2 for Star Performance. Jim knows his way about Audi's and has translated this into countless numbers of Golf's. Every time I've been (for cruise control, servicing, etc) there's always been a couple of Golf's, Skoda's, etc there.
Or in Edinburgh, Autohaus are Revo Stockists I think. Never took my car there but their unit is always tidy and smart and they get a good report locally.