I just added some texture layers (see pics) above the screenshot and experimented with different layer filters and lowering the opacity. A good place to find textures is http://www.mayang.com/textures/
this could look way better if you have the side lights and the taillights light up the ground around the car; would look great, and also if you made the taillights brighter.. i think it would look much cooler
unsure about the lighting on the car though.. unrealistic sure, just trying to figure out how to make it fit in better.. i guess if you made some lights around the track slightly could help it look more in-place