2 suggestions, firstly make sure the S6 has a solid warranty that covers the drive train and second check the transmision has had oil changes every 38k miles religiously. As others have said there are many transmission specialists around the UK who will fix a faulty S-Tronic box for a lot less than an Audi dealer will charge. This would probably be a good starting point http://www.fedauto.co.uk/Thanks for that. Not got an S6 yet but just doing a bit of research and considering my options if it goes pop. Especially if I get it "improved". Suppose £10,000 is worst case scenario.