I don't know if you have done this yet or not...
Front tyre is wierdly wide.
Rear lights arent even, the boot crosses one but not the other in the correct place.
Mirror looks dodgey.
Rear tyre on the right has a layer over the top of it.
Front tyre on right is attached to bumper?
The covers on the headlights need a bit of texture, they just look flat where the bonnet and wing leading to it have a line down the middle with light shining.
Need some detail in the bumper grill, the black looks a bit dark
Also, try to blend in the black you have used on the tyres.. for the brush, and sort the shape of the wheels. Also tuck in the front wheel from behind as others said
I am good at criticism. It looks great, but as the other guy said, for a magazine comp you want perfection.
Oh and dewiper it
I think I am done, but that aside it looks great so far.
Edit:
Door handle still on the rear shot