I've done some revisions to the SketchUp model - the sides taper much more in the back, and the 'A' pillars now curve toward the center a bit more. The rear wheel track is 6" narrower than the initial version. There are still some rough areas, but overall I am very happy with both the way it looks and how low drag I think it would be, as well.
Here's the same animation sequence of the SU model:
So, who wants to start building this car?!