All the work is done by the dummies (also known as null, helper, empty, etc) and their naming. The point is, do not be distracted by the visual mesh. while what you actually see, could be this. *a bunch of dummies with specific orientation and names. Under the hood, a complete working car looks like this (selected cube being the front left wheel): But from AC engine's point of view, you could drive a cube. Well, it matters if you want to make a top mod, and boost immersion, of course.
If you're anything like me, then please keep reading. I personally like to start simple and once that is clear, continue to build on it. And that makes it not so straight forward to succeed with your first car. But it concentrates too much on the graphical side and not enough on the rest. It's long and complex, and has a lot of useful information. Example - the car_pipeline*.pdf directly coming with Assetto Corsa (typically under \STEAM\steamapps\common\assettocorsa\sdk\dev). However, I feel they don't treat the subject as a whole. There are already tutorials on car modding for Assetto Corsa out there.