Looking pretty good! I'm no expert but I'd be a little concerned over all those three sided polys. They are adding an awful lot of polys without defining the shape of the mesh too well. Sorry I'm not explaining too well! I'm pretty much a beginner with no experience of this kind modelling but I think you would learn a lot from looking at other peoples car meshes. I'm sure a more experienced modeller will explain better. Sorry if I sound negative, I think you've done a great job but would find it easier with a different approach. Baz