Give us some car setting examples for each type. That way I can tell what you are doing wrong with your car setup.
To add, you might not have good car control, probably due to poor acceleration control, and not braking at the right time. Go back to the license tests, and do them over.
For the easiest FF car, use the Xsara Rally Car.
For the easiest AWD car, use the FTO LM Race Car.
For the easiest MR car, use the Raybrig NSX JGTC.
For the easiest FR car, use the Castrol Tom's Supra JGTC.
Note: Easiest means easy to use, and control, not the quickest car for that type of vehicle. For MR, you could use the F094/S, but some people find the F1 cars hard to use.