As you were building from scratch, could you not have considered making it a pop-top to reduce frontal area?
It does look a very nice shape however...
I've always hankered over a small tear-drop shaped trailer/caravan, that we could tow easily and over-night in.
Seeing your method of FG over foam has the wheels turning and thinking maybe I could build my own...
http://www.365campingcaravanning.com...d_trailers.htm