This is super stuff!!

The colour combination of white black and red works a treat, and those new rims are stunning

There are just a couple of small things that you must fix first though:
->The tyres are too dark on this side of the car - it has the effect of making it look like its just been pasted on the backdrop - look at the car that was on your bg for reference, and try and change them to match
->Considering the long strong shadow, the left side of the car is a bit bright
->The rear wheel is a little bit off (it's slightly too wide) - but this shouldn't be hard to fix
Only small errors really - but still i really like it

Well done!