It would be nice to know a couple of things about what you want in your race game. (1) viewing angle; (2) how you want to control speed (not just keys, but specific behavior as well); (3) layout of track; (4) etc.

I am sorry to say that at the moment, I do not have any demos on controlling a car. That would be something to consider. At any rate, your smoothness is not that great. At slow speed, only few angles of movement will be achieved. Also, the turn rate should be governed by the speed -- not just to turn or not turn, but how much turn allowed dependent on speed (no speed means no turn; slow speeds would be close to maximum turn -- minimum radius turning; and faster speeds would diverge from maximum turning -- larger radius turning). For smoothness and for full range of movement angle at any speed, consider using my QActor class which can be found in my Asteroids w/improved QActor Superclass game scenario.