We call the car dealer's repair area "house" and it is expensive to have your car maintained there. But on the upside of the "house," the quality if unquestionable. And since our car is only 3 years old, we have the regular maintenance every 4 months in The House. However, when it comes to replacing parts, we bring the car to an independent garage that provides repair service. Take for instance the brake pads which costs 15k in the house, the independent garage charges only 5k for the parts (they are also original parts).
That's because it kind of a garage that doesn't pay any bills or taxes, unlike the other one where they pay taxes, bills and also their employees salary. It's good when you have a trustable mech to fix your car when you're in a need, these are really good because they're cheap, quick and good.
If you live in the U.S; you can request a service online that offers available hired mechanics to come over home and get a price to repair the car. And since they don’t have the overhead cost of a shop, these kind of services are able to charge less while providing a convenient service.
I have heard some pretty serious horror stories when it comes to this, but I actually have never really had much of an issue. The typical thing that I hear is just overcharging in general, but every time I have needed repairs, I make it a point to get other estimates and they are pretty similar. Maybe I just got lucky and have a good dealership, so they are out there.
I wouldn't trust it that much personally unless it was a close friend of mine but even then I'd still probably mostly go for an official area where I can be assured of the quality of service and goods and be assured of the warranties and guarantees as well. Even if it would be cheaper for me to just get my car fixed at some guy's garage, when I'm dealing with a product that is expensive like a car I try to just use the officially endorsed services as much as possible so that I don't end up damaging my expensive item.
I opted out of owning a car very many years ago. It just wasn't worth the expense to me. When I had a car, I was the only one riding in it most of the time. The other seats were so unused that spiders built webs in the back seat. I find a motorcycle to be so much more convenient and so much cheaper to maintain.
I agree that getting your car repaired at authorized garage is bit costlier than going to a independent service center but you get specialized car care by company trained engineers/mechanics which is an advantage besides the authorized service centers is a guarantee of original parts too.
