Come on Lincaz, thats not constructive and we all have to start somewhere.

Start off easy. try to find some bodykits and copy them onto the chop, if you don't have donors have a look on donor central on autemo or Google. Then on new layers try brushing, but always look at the base image as idea of what color and brightness to brush.
But first master the basics before brushing, because it is very hard.
So start easy, like background change, brush vents, carbon fiber, c/p bodykits etc.

Good luck and keep chopping

if I can add that my Friends already said, here..

hope this will help..

Their is a lot of room for improvement on this chop man. I would stick to trying to copy and paste as much as possible as you need to learn colour matching quicker rather than brushing (this will benefit you in the long run). Your side skirt and front lip is are very edgy and the colour tones are wrong too. Alot of mistakes around the background due to you lowering it too. Take more care in your work man. If you need one on one help, let me know, I'll be glad to show you room for imrpovement.

Keep it up and don't give up.