[QUOTE=mike.t;1194792]Major. Blunt?[QUOTE]
Blunt = not pointy
...the whole "wind deflection/control" thaaaang
The aerodynamics of any RV -- of any kind -- is lumpy, bumpy, and lousy.
Virtually all the resistance comes from the suction turbulence at the REAR of the unit, but not obviously realized.
If you REALLY want to decrease drag....either:
a) add a long pointy extension to the rear (a la any aircraft you have seen), or
b) add 90 degree deflectors to the top and side edges to direct air across the rear.....has the added advantage of keeping the windows clean.
Easy/best way: Just know where the "kink" in the resistance curve is and make that your mph sweet spot
Mine is 62 mph.