Short: How do you tell a friend/family member they're wrong about something automotive, but respectfully?

Long: I've been living on my own for about 6 years now: once I had a decent paying job and was fully able to support myself. Turning 27 this year. I was chatting with my dad on the phone, and I mentioned that I had to replace rear rotors & pads on my car (2011 Mazda3, the rear rotors are scored and beaten like someone took a hammer to it, pads are worn at an angle. Severe clanging noises and car shakes from the rear when braking and slight scraping just with normal motion. Calipers might even need to be replaced) along with the leak in the AC system and other gremlins.

He immediately became agitated, and his response: "There's nothing wrong with your car. It's a reliable car. You're wrong."

Keep in mind, this is the same guy who drove his truck around for a year with a transmission that wouldn't shift into 4th gear, and only sometimes would shift into reverse or park, and said that was "fine". Or buying the wrong brake pads because they were a few bucks cheaper and he "could make them fit". But it's always been like this. The only time something is wrong with mine or my brothers' vehicles is when he deems it. 

Now, he hasn't even sat in the passenger seat of my car in 6 years, much less lived with MY daily driver. And yet without looking or listening he's making wild claims that nothing is wrong. He clearly is full of it, or thinks that the car needing any work is some sort of personal offense against him. Some folks just won't acknowledge anything that might make them seem wrong....

How do I respectfully point out to him that what he is saying is ludicrous, in a way that actually changes his mind, but without crossing the 5th commandment? Driving cross country to my parent's place, paying a mechanic to make a house call inspection in an ambush style "I told you so" confrontation seems a little bit much, though it's crossed my mind.