Well, it's what you get when you push the 'aerodynamic trailer' hot button.
Thanks for the opportunity to hi-jack your thread. If you combine the squircle and that gypsy wagon with this:
you've got my current thinking on a teardrop—the Aerodynamic Template rendering in curved fiberglass rod. It would have a inner lined with the rods through sleeves and then a sock pulled over the outside.
You could think about the plan taper starting at the tow vehicles rear tires. Swap your pickup box for a utility bed with outside storage. Then round off the rear corner lockers following Mair.
The house-on-a-truck had a custom flatbed with curved sides. And he is 6'5" so he made the roof shoulder height and then put a plexiglass bubble at the center top that fit him like a hat.
For the overhead storage look at
aerohead's post on canopy drag
Edit: Here's a rear trailing edge by Luigi Colani for one of his Bonneville racers.
The lower scallops act as endplates for a divergent duct, then the sides are cut away for better sight-lines. The long, flat duck-tail comprises a box cavity. The backlight is flat on the bottom but about 120° of circular arc on top. And angled back so the whole back of the car is a diffusser.
Also, PVC and fiberglass are nasty stuffs. What about redwood and cedar. Or prefinished sheets of something? My vote for better materials/less finish work would be
bamboo slats rabbeted for Polymetal fill panels.
