About streamlining--think of a fish or airliner--blunt rounded front and pointed tail. But if you tow at supersonic speeds, streamlining gets different. 
If I REALLY wanted a streamlined enclosed trailer, I would look for an older, bad interior Airstream or Avion travel trailer and rebuild the interior to suit.
Bruce
If I REALLY wanted a streamlined enclosed trailer, I would look for an older, bad interior Airstream or Avion travel trailer and rebuild the interior to suit.
Bruce