I have all maintenance done at the dealer, on all our cars, and keep every receipt in the owner's manual folder. I keep the owners manuals in a file cabinet, as they are only really reference material after you've memorized them upon delivery.
No, seriously, after you have learned how all the trinkets work, do you ever look at your manual again, except for possibly a maintenance schedule check? The original owners manual folder is very heavy duty, always fits well in the glove box, since it was designed for it, and is always there to stick that receipt in, as soon as you get it.
I've found, in my more mature years, that the dealer really isn't that much more expensive than indies and it is ALWAYS the preferred place of possible buyers and IS NEVER QUESTIONED when you trade the car to another dealer. When you trade the car to the dealer where you bought it AND had every single oil change and maintenance done, those few hundred extra dollars are the GOLD STANDARD for trade in value because that dealer now has a used car to move that has a GOLD STANDARD history of maintenance, as wellas a great testimonial for their service department, and you all know what that would be worth to you, if you were sitting in my black boxster, dreaming of making it yours.
If you're lucky, the salesman will tell you what I traded it on.
Mine was the original customer's first Porsche and he traded it on a 997 after 9 months and 10,650 miles. He then traded the 997 after 7 months and 9k miles on a Cayman S.