NeilBlanchard wrote:That Mooncraft Prius is impressive - very well done aero mods. Make the rest of us look like amateurs. The back is a excellent example of a Kamm back, which has a tapering angle, and then a clean edge so the air separates without tumbling.
For experimentation, the favorite material is Coroplast, which is the corrugated plastic sheets, like what yard signs are made out of. It is ~$20 a 4x8 sheet, and it works well enough to test things, and then you build things out of aluminum or fiberglass.