The Hucho book has the plan view of the Schlörwagen:
By the way, I started doing a SketchUp model with this image and I am almost certain that the 1275mm height should go to the underside of the chassis, not the ground. That is the way it scales, anyway.
Here's my collection of the best Schlörwagen pictures:
Schlor Pillbug pictures by NeilBlanchard - Photobucket
Going by the tuft test in the wind tunnel, there would be less drag if the tail was broader and flattened, like a beaver tail, and/or if there were rear wheel strakes.