Well...I'm going to be honest here. I don't know if this is your first chop or what because there is no text with your post...but there is some work that could be done here.

Please dont be offended but here's my list of things you could work on to make this a pretty decent chop. Again I am only trying to be courteous and offer a few suggestions.

First thing is the perspective...if you look at the bricks on the ground of the bg they do not line up with the car. The angle of the floor of the bg would make it so you could see the entire roof of the car. On top of that...something feels wrong with the bg because that manhole cover in front of the car is skewed pretty bad.

Second would be the reflections...you tinted the windows, but there is no reflection on them witch makes them feel flat. A tinted window is going to reflect a better picture than a normal window. So there should be some of the bg reflected in those windows...as well as on the car.

Some of the smaller points would be things like...you removed the antenna on top of the car, but the shadow of it is still on the upper wing. Next, if you look at a 2 door and 4 door version of a factory car, you will see that the 2 door has a longer door than the 4 door. So when you removed the back doors, it would look more realistic if you were to stretch the front door.

On a positive note...I feel like the lighting of the car matches the bg pretty well. And the new exhaust/diffuser seems to be at the right angle.

Keep at it...there is a few things to work on, but with a little work I think you will be on your way

luke_jones said it all!

If you add more shadow under the car, it would look 10 times better