Nice so far - the ideas are great, and it's looking damn cool
When you come to the paint though, you need to make sure you add in plenty of bright highlights and use the correct colours
http://img.netcarshow.com/Volkswagen-Golf_GTI_Pirelli_2007_1600x1200_wallpaper_02.jpg
Use that for reference - take colour samples, and brush similar reflections to create the effect of shiny paint.
If you're not sure how to do this you might wanna try my brushing tutorial (click the link in my sig). But yeh - just use this as a sort of basis for your paint