I have zero real-world knowledge about cars, or how they work.
I do not have any idea how accurate the parts in the game would relate to the real-world, but I figure it has to be good enough to give you a pretty decent overall idea of how cars work, and where parts would be, and how all the parts fit together.
That being said, I really like this game! Each work order requires you to think about the problem, and then identify the right part, find out how to GET to that part, and then either repairing the part, or replacing it.
The interface/controls feel slightly awkward, but still much better than many of the other "____ Simulator" games that have been coming out recently.
Even if you don't really care about cars, or how they work, this game can be highly enjoyable even from a simple puzzle-solver perspective. For me, it's even given me a different perspective about how cars work.
I don't expect to suddenly look at a real-life car and know how to take it apart, but maybe, just maybe, I'll at least not be so blank-face dumb about it. Not that it's a required part of playing this game, but hey, you may learn something.
I definitely recommend checking this game out.