Cheers for the reply Matt.
I managed to find a garage based in Ashford Middlesex called Boxer Motor Works.
They are a Bosch Service centre and specialise in the servicing & repair of Audi, BMW, Merc & VW.
http://www.boxermotorworks.co.uk
I recently had an MOT and subsequent repair work carried out by them.
I found them to be a pretty straight up outfight and at £60 pounds an hour labour almost a clear £40 quid cheaper than my local stealership.