car game

I have always loved that tutorial, however, a few things I am wondering.

  1. If the car is on its side, it turns as though it is right side up. What can I do to fix this?
  2. If the wheels are not in contact with the ground, the controls have no influence upon the rpm of the wheels. How can this be fixed?
  3. How would we get smoother rotating of the wheel? Would IPO’s be the answer for this?