19 years old?? Change your own oil man!
Dealer trust? That's a pretty general statement when there are so many different individuals that can work on your car.
I had an experience recently with a friends VW that came to visit us from out of town. Before she left she had VW perform an oil change and air filter. As with all of my wife's friends who are towing 1, 2, or 3+ kids around I always offer to check their car out before they leave my house to return home. What did I find when I checked out that Golf 1.8T? You won't believe me, but here were the results:
1. Giant flat head screwdriver (12+ inches) laying over the right front strut assembly. Just sitting there.. no word of a lie. I asked if it was hers, and she said not a chance. She was going to go back to the dealer and lay into them for that 'mistake'.
2. Tires were WAY over inflated. All four tires had different pressures ranging from 40 - 55 psi.
I asked her for the invoice of the VW service to check what they did, and total was $120 for oil change, air filter, and general inspection. What a mess that could of had serious implications.
NO ONE touches my car but me, and if it has to go to the dealer I insist that I'm there to watch. Sorry, my safety is worth more than convenience.