I’m curious, because I wonder what people outside of this forum think of car dealerships?
Unless you have money and don't really care you don't ever bring your car back to a dealership for service and the ones that do don't have to worry about money and can be sold the gates to hell. They make very little selling vehicles their bread and butter is the back room. You have some foolish notion about them selling you a service when you don't really need it.
The reason most vehicle manufactures have now changed the rules to only their dealerships servicing your vehicle is because people got hip to the game and the dealerships were loosing money.
Your father may be smarter than you give credit for. He's probably been taken advantage of a time or two in his life.