To the OP: On
www.ecomodder.com Check this thread out:
http://ecomodder.com/forum/showthread.php/aero-rv-custom-boat-tail-95-ford-e-18151.htmlThere is an an aerodynamics thread, with a person who started working on aero on a class C. Specifically, he was working on a boat tail, belly pans, etc. Haven't looked at the thread in quite a while, but it was a good read.
It also included some good aero links, one in particular regarding having rounded lead edges vs 90° corners like most campers have now. Rounded was much better, which explains airstream's claims of better gas mileage and towing stability.
This should hopefully help you out a bit in your quest.