Each dealer has their own guidelines to if they cgharde the customer the trip/service fee. Some dealers do not charge the customer this fee, which is an added benifit to purchasing from them. Most dealers get a very minimal amount for the labor, and it is paid with credit, not money.
I know it stinks, I purchased a used jeep with a bumper to bumper warranty that I have put 4000 miles on and have 3 "deductables" of $100.00 to pay, plus I have to bring it to them. Drives me batty!