you have way way way way way... etc. to many polys in random places so lets begin
the roof.. you could probably cut out half of those polys and it would look the same (if not better; but .. usually its better)
the door; well, especially near the door handle, all of those that go down can be turned into quad triangles and then to single lines
spoiler still has that weird triangular shape, it should bend, not angle at the center
hood looks okay for the amount of detail in it so .. i'd stick with that, there are a few things that could be changed to clean it up, but nothing that would affect the outcome
nose looks fine
fenders! (made this next section smaller because i noticed a bigger problem than the following)alright here we go, not exactly the fenders that stick out, but the area that forms into the fender, especially the rear is a HUGE problem and creates plenty of bumps all over the place, a good fender would be one that extends outward in a circual form; not vertical and horizontal lines
-actually now looking closer, what may be causing that is all of the triangles and n-gons, i bet if you fix that, and then smooth it, and use a reflective material and view it in perspective and spot out the bumps, you can clean it up quickly
