White is one of the easier colours to brush in my opinion as you can brush purely in greyscale and add slight hues to it instead of having to brush or copy full refs.
What colour is the car in the background? If it isn't white you can still use for it rough reference of where refs should be, such as horizon line.
A few problems I think the need to be solved, the side needs an horizon line added with the top half of the side being alot brighter than it is. I think the side needs to be less yellow / orange and more neutral / blue hue.
See this pic:
http://i6.photobucket.com/albums/y249/danhurwitz/Mach%20V%20Cars/STI/D-Force/Sunset1.jpg
The front is quite neutral with a slight blue hue but the side where it is reflected the sunset are yellow / orange coloured. Hopefully you understand me, if not I can mock up what I mean later.