Well I'm only 5 months late replying to this one which if you have seen any of my other posts is a speedy reply!
I had both of my diesels done and the post shown in the link below is the one that pertains to your pre-facelift;
http://forum.a8parts.co.uk/showpost....56&postcount=5
I have also had the facelift mapped with even much better results.
I've heard it said if it has 4 rings and a turbo the only place to go is MRC in Banbury!
Hope that helps?
Regards,
-=Glyn=-