Original:
http://www.seriouswheels.com/2010/r-z-0-9/2010-Saleen-Ford-Mustang-S281-Side-Angle-1280x960.htm

Chopped

you definitely not a new guy in photoshop world!

welcome to autemo

lsd door is cool but you have used a wheel for front and rear both
rear one is off now and wrong in perspective
just try to find a suitable donor for wheels and fix it

you need to add some shadow under the car between
7/10

keep it up