I am currently trying out their Firefox Personas:
Personas for Firefox | Dress up your web browser

Changes the top area and bottom area into a color, pattern, picture. There is a carbon fiber one:
Personas for Firefox | Persona Detail

There are only a couple of auto related ones in the Sports section. But NO FITS!

I have not tried to "make my own" yet. But, I bet someone here could do a way better job anyway. LOL!

I'm thinking there could be one especially for FitFreak.net. And perhaps people can make ones of their own car. Or create a collage of all the colors. It would probably have to be OUR OWN PICTURES, not images swiped from the Internet.

Even the aftermarket companies could get in on this. Creating their own Persona that showcases their products. Check it out and see what you all think.