red color is too saturated for me, and front bumper looks like it's part of ground, try to put some more and stronger shadow underneath and it should looks better.
like was said before, rims are too small and some parts looks toony (sideskirt, pillars, red parts of roof)
i'd make back of car darker... i actually made some quick brightness/contrast and saturation adjustments as well as black gradient on low opacity from back bumper all way to front wheel for some better fitment in background and it looks better for me.
pretty nice work tho.