yes it does affect the warranty, so stick to main dealer service until it expires, then shop around and save some money. i really believe that anyone who uses main dealer service after the warranty has expired has too much money. (thats just my opinion, but based on the facts that as a mechanic working for an independant garage, and also knowing lots of guys who work for dealerships, i know that it doesnt mean you get a better service, in fact only speaking for myself here, it works the other way round) the bonus schemes that main dealers employ for thier mechanics (not all main dealers) works on a time/production system, meaning if a service should take 3 hours and the mechanic does it in 2, he earns points etc etc (something like that) and vice versa if it takes him 4 hours he is penalised and has to make it up on his next job. we dont have a bonus scheme, so if a service takes me longer than the scheduled time i win or lose nothing. but it does mean i have more time to properly service someones car. i truly believe you are paying for a main dealer stamp in your service record and nothing more, i wouldnt work for a main dealer if they offered me twice my salary, i appologise to any dealer technicians in here,