I started playing F1 in rfactor and man, car setup is a pretty big science. No way could it be covered in game by tooltips or something. If you want to know how to setup a car you need to study it. When it comes to open wheelers, there is a certain order how to setup the car, e.g. start with the wings etc.
Anyway, I was thinking it would be cool though, if there would be some kind of "data box (perhaps like a chart)" so when you do change settings, it will show you what are you losing and what are you gaining, e.g. changing the angel of the wheels would reflect on straight line speed and cornering. Benefit of that would be the fact that you would have a visual feedback of the changes and the areas they affect. After few laps you would start figuring out whats the difference between the settings and the way they affect the performance. I think this would save a lot of time, especially for beginners not to mention people would not be put off by the complexity of the car configuration. wow. I this came out long. I hope my idea gets through and somebody will actually bother to read it