There are quite a few Audi / VW specialists in the T Wells area. I have used Martin's Volks Works in High Brooms (North Farm Road) a few times. They do a good job there and always seem to squeeze me in at short notice. He's not particularly cheap though. I bought my first car (Audi A4 1.6 SE) off the guy that owns it (Martin!).
Otherwise theres another one, John Bowles, on the high brooms industrial estate (if you know Tunbridge Wells you might know what I'm going on about). Havent used this garage but my friend who had a VW Golf Mk2 in the family from 1986 till last year always went there and recomended them to me.
Theres also Alltech Garage services who I have heard very good things about from my friend's Dad who has a Seat Leon Cupra. I think they are mainly a tuner (specialising in VWs, Audis and Seats) but its probably worth checking them out for the work you want carried out. They are located along Upper Grosvener Road, just near the bridge over the Railway line between High Brooms and T Wells.
I think there are more, possibly the garage near the bus depot along St. Johns road is a VW/Audi specialist, although I havent used them. not 100% sure of the name either.
Let me know how you get on as my car needs the Cambelt done ASAP and I would glad to know what sort of prices some of these places quote you. I am thinking of taking mine to Stafford Audi (a main dealer) as they are advertising on eBay that they will do a cambelt on any 20V Audi for £275 (do a search). Its a long way to go but it might be worth it for the saving, as Audi Tonbridge wanted more like £550 to do mine when I asked them.
Mike