I think more depth in the steering, like being able to drift or do deep turns could really add to the gameplay. It's fun, even if the car's handling could be adjusted a touch. Also, the volume's a bit too high for my taste, so being able to adjust that would be nice. But otherwise, the polish is great and I really appreciate the commitment to making the assets yourself.
I have to say the game is the most unique take on the theme so far, the presentation is superb and the game is a lot of potential.