Driving a rectangle as I do, I've thought about this. I figure, I could get more bang for my buck, particularly at higher speeds, if I had a modest single-wheel teardrop trailer (it can be towed much closer to the car than a conventional trailer). You might consider the same.
Of course, I'd have to actually acquire/build one to try it out, but anecdotal evidence suggests that a teardrop behind a brick helps quite a bit.
__________________
|