Thanks for including simulations in the topic.
I think comparing the vehicles in a simulator would reduce a lot of variables, and provide valid comparisons. That said I'm not part of that culture; although anyone with an Android phone could be:
Camper Van Truck Simulator: Cruiser Car Trailer 3D - Android Apps on Google Play
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As a standard RV-sized aerodynamic load I propose:
An improvement might be a boxed cavity on the back.