Last 2 evenings I worked with Blender (about 3 hours. Now I don't have too much time).
I found 3d-lessons where a man does Opel Speedster 2005. There are 28 parts, and I have finished only 3, but it looks pretty well.
lessons (in Russian:)
*my car will owe to looks like this one *
I saw many cars have made by this course and they looks great. Someone even sell it in 3D-stocks (70-90$. I think it too expensive for other people's work.). But I would like to have this skills. =)