Looks good but the reflections on the above material need some tweaking. Here's a tip I picked up from a tutorial for all those using Max (and you should be able to apply the idea to other programs).
The reflections on a car body change in reflectivity depending on the angle you are to the body (or surface). If you are looking straight on at the body the reflectivity will be less than if you looking at it down the plane of the body. Pic 1 shows this more clearly.
In order to simulate this, you can apply a Falloff map to the reflection channel, change the falloff type to fresnell and you've basically got it.
Now to explain the graph below. The x axis is the reflectivity where black is not reflective and white is highly reflective. The y axis is the angle at which you are to the surface with 0 being straight on and 1 being a very small angle to the surface. As a car body is never totally reflective I move the top left point down so that the paint is never totally reflective.
Any questions feel free to either post 'em or PM me.
On an additional note I am quite new to this so this method can probably be improved upon somewhat.