[2FastLX]

Drew,
Check out that web site cad614 posted and take a look at the tutorial on converting a black car to white. That's the way I do it and it works. Going all the way to white is ok, but I find it works best to take a car to a medium gray for the most realistic looking paint jobs in the end. Otherwise you can sometimes lose too much detail depending on image quality.

I see you took the tute one step farther and started messing with some gradients. Very nice! The only things causing your paint jobs to look oversaturated is the fact that you are working with a black paint job underneath. That's what is causing the "colored chrome" look you are getting. What's happening is the car is so dark that the color overlay is making it look like the image has too much contrast because the black paint is hiding the shadows of the car.

Lighten the body up a bit by following that tutorial then play with the saturation of the overlay layer by either lowering the opacity of the overlay layer a tad, or go to IMAGE>>>ADJUST>>>HUE/SATURATION and tweak the overlay layer until you get the desired effect.

What you have done is great though. Your selection of the body looks to have been done very well. Now since you seem to have the selection tool down try this - Increase the image size to 2400 pixels by whatever the proportional heght comes out to. Then try a flame selection and lets see some flames. Increasing the image size makes the selection tool a LOT more accurate.

Hope this inspires/helps you out