You made an interesting choice by combining a 3D environment with 2D Sprites for objects, backgrounds, and the car. I like it! It's quite unique.
The game itself is a bit rough around the edges. I managed to fall of the first track and there was some flickering on later tracks. But I think is you would polish it a bit, improve on some of the track designs and make the background a bit more interesting, it could be a nice little game.
Well done!