[Christ]

First thing I noticed was that the trailer was essentially an extension of the bug's rear profile with a "hat" section.

I bet that could be made completely aero, especially applied to trucks which might have a "quick" fifth wheel hitch... trailer doubles as a bed cover and boat tail in that case, and unhitching the trailer leaves you with an empty, uncovered bed for work days, satisfying the "I have to put stuff in my truck" argument.