AFAIK, in general there is no need to go to a Dealer to keep the warranty valid, but be prepared to show that the maintenance was done by a qualified individual if there is trouble so they don't have a good excuse to wiggle out of warranty work. (Check you warranty manual, of course.)
Having said that, it may be a good idea to cultivate a good relationship with a dealer in case something goes wrong. That may well be worth a few hundred $$ of overpriced maintenance.
Having said that, if you read enough horror stories about dealers on this forum you may reconsider.
Guess that wasn't too helpful, eh...?
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