I think I would be able to see and enjoy more of your unique gameplay elements if the following were addressed.
1. When the taxi cab collides with the world geometry, it's a very "sticky" collision that stops the car almost entirely. There are collision detection and response algorithms which allow the player to smoothly glide across surfaces, and I would certainly put one of those in this game.
2. I'm not sure if it's your engine, but I did notice occasional flickering and the seams of tile areas showing up.