+1 to what mvb said.
also in my experience yes its good to have dealer stamps, esp when selling to numptys in the future, its the first they look at, and fair enough. but the older the car gets, the less it matters I would say, after 6-7 years or so the car will have devalued considerably and people will buy on condition more it having lifetime VW service.
saying that mine is 6 years old this year, im first owner and its still only got 27k on it!
Although I have kept to VW for servicing since new, and also in and around london, i've used various dealers for mine and my sisters cars. I have to say some are crap and some are excellent. but it goes without saying, they ALL want to make profit out of you, so get everything in writing, including the quote for a service, and get everything stamped up and keep invoices. Its good to have the backing of VW, however VW customer service are about as useful as a chocolate teapot, as the dealers are franchises and behave how they want.