the ersan-tag's shadow looks like a photoshop (and thus not pixel-art) to me..
elsewise nice little car, i like the cartoony look, although a few things bother me (additionally to the shadows =).. first the aa - it's is too smooth and the single pixels between the bright and dark parts of the car in the sideview don't fit to the overall look really - i recommend adding one more color there; second thing are the wheels of the sporty one - they are mirrored (no-go) and deserve some metallic shading i think.. 4/7
Looks good to me. I guess there are supposed to look a bit cartoony :)
You might want to lighten up the shadow below the text, it's quite hard to read at the moment...