At first glance I thought it looked awesome. Now I look more and it has so many problems.
Spoiler is off; should be more to the left.
Rear bumper; looks fun-finished.
Side rear passenger window; no refs, their should be.
Front passenger side window; top half is wrong refs.
Wheels; Rear one is off and stuffed under the arch too much, front one needs turned anti-clockwise a bit.
There appears to be like a black blob at the front tyre and attached to it looks to be an un-finisheed front bumper too.
Side skirt has in door refs plus their wrong. They shouyld be reflecting the ground.
Crown graphic on the boot lid from personal choice I wouldn have left the boot smoothed.
Rear window is also too black.
However, I like the ideas you had for this, just seems a little rushed. Colour choice is rather nice and the background suits it well. You can do better, you have half decent brush skills for a new chopper.
Keep it up.