This is a fair start.
Here are some things you may want to consider for your next chop.
Perspective is EVERYTHING! You need to maintain your perspective throughout the chop.
Here's the original with perspective lines.
Here's the chop which is considerably out of perspective. Same perspective lines. Note the body and wheels. That front wheel is way out of shape and seems to have two treads, one of which is coming off.
Chris pointed out lines on the front of the door.
In addition to the headlight being out of perspective (as Chris stated), take note of the running light I've colored in red. In the before image it's in perspective. In the after chop it is not. Be aware of the details.
Before
After
Note that the car in the background has been blurred but as viewed through the windscreen, it is in focus.
There seems to be some clouds reflected in the door rather than smoke...........but I get what you were trying. The rest of the car seems to have a matte finish so the door would not be reflecting much at all.
I whole hardheartedly agree with Chris that this front left fender body work is not realistic or rational. What would it add to the aesthetic or performance of the car?
Unless you were the original photographer, you have pruchased the rights, or asked permission, be careful adding your signature to someone elses copyrighted material. Even though you made a few changes, you do not have the right to claim the image as your own. The original artist/photographer can still prove that this was his/her image. You should always credit the photographer. Food for thought.