Change background man

lost a bit of quality
directly under car shadow need be darker
and under wheels some more shadow too.
try to find some foto where u can watch how have to look
middle part of cage to black. need bit softer course.
maybe looks at the tut from Veer in forum...
http://www.autemo.com/forums/?t=21167
lights are better, bg is ok imo, just shadow is problem... and colored rims are not that good imo. u colored all also the black intakes... and bit unclean where chrome starts...
Add some contrast to carbon parts.

some points I tell u but I realy like the style and what u did.
try work bit more clean, and find some reference pics.

Keep it up