Before:
After:

Those neons make car fly if you put them this strong..I think that removing neons and puting some proper shadow would do much better job. (For shadows tut check http://www.autemo.com/forums/?t=12640) Brushing goes in a good direction The car is slightly out of backgrounds perspective..

I like your ideas. The cars color is good, and your brushing is going in the right direction. But the neon lights don't look completely right. They look to strong, and don't really suit the car really. Also, the front grill doesn't quite fit right.. And as mentioned, the perspective is a little off. The rear wheel looks flat, but they suit the car. Other than that, awesome work. And just try and improve on those little things .

Your idea is good, I like Shelby stripes on a Mustang. They look awesome.
But your chop could be a little better. You haven't made a lot of chops, so I'm sure you grow a lot when you keep posting stuff on here.