Body dimension guidelines shouldn't be too difficult .... roof height, rear deck height, front end length past front axle, width, greenhouse volume, etc.... Heck, we already check a couple of these anyway. Unless the sanctioning bodies step up with more stringent guidelines, the "body wars" will produce unrealistic shapes that cause one-body races (aka: Parma Alfa on carpet).
I'm all for standardizing these measurements AND letting the body manufacturers mold the rest of the shape to meet their desired performance criteria.
p.s.- G6 on order