Just a quick post to wholeheartedly recommend the services of Chris, a motor-sport engineer, all-round VAG enthusiast and nice chap.
His prices are *very* reasonable, he's extremely knowledgeable & has an impeccable work ethic. If you're looking for a specialist in the North-West London area (Golders Green), I'd like to point you his way.
If you give him a bell on 07906-172348 & let him give you a quote - I'm sure you will be pleasantly surprised.
I wish him all the best.