Working for an aircraft company for 30 years I have built and witnessed a few wind tunnel trials and in later years computer simulations. It is not hard to visualize the turbulence coming off the back of a MH. When I went to Alaska I built a shield that went from underneath the MH to the tow car out of old trampoline material to keep the stones from damaging the tow car. Similar to a protect-a- tow. I always wondered what the difference in mpg would be if the material went from the top and sides of the MH to the back bumper of the car creating a trailing edge to lessen the turbulence and protect the whole car at the same time. It would be interesting if anyone had any information and could relate what a 25% reduction in wind turbulence would have on mpgs.