Car audio repair - Glasgow/Edinburgh?

[Steven944]

My mother has a 2000 Audi A3, and I'm trying to find a car stereo shop that can repair the volume control. It's a familiar (well documented) fault with the old Audi stereos, but I can't seem to find anyone that can actually DO the repair. Plenty of 'you're better off getting a new stereo', but I want to keep the dashboard the way the factory put it together....

Any recommendations?

many thanks
Steven