Aerodynamics are kinda the Achilles Heel of the Vanagon, aren't they?

 There's a guy here in the Columbia River Gorge (windy place) who drives a
much modified newer Dodge van..Totally silly looking, but well done and it
probably get him a few mpg more.  A big ole cow-catcher splitter on the
front with about 2" of ground clearance.  Full skirts on the wheel wells
mounted with Dzus fasteners.  A slick belly pan on the bottom, faired in
mirrors and best of all?  All windsurfers have to carry a bunch of gear, so
this guy has a gutted out upright freezer mounted on the back on the right
side for all his sails and stuff and carries his boards upright on the left
side..all down out of the airflow...

  The vanagon, I don't see much hope for big improvment in Aeros.  Mine,
I've kept the top low and when I have a rack full of bikes, I mount it on
the rear hatch.  Thats about all I can see to do easily.  It's certainly
amazing how much drag even the smallest protrusion creates..stuff like cargo
boxes or spare wheels on top...
  At Vanagon speeds, it's not too huge, but here in the Gorge, it's common
to see apparent wind speeds across your vanagon at well over 140mph.  Going
down the interstate at 75mph and get hit with a 70mile an hour headwind
gust..There are pieces of RV all over the interstate to prove just
this...Shredded awnings, Air conditioner covers, the walls and roofs of
those rolling slum double wide modular homes...
  Totally off topic:  We used to compete our Porsche 928 in the Open Road
races over in Nevada.
http://www.openroadracing.com/
We ran in the Unlimited Class eventually, at speeds of up to 200mph. but at
one Pony Express Event we were in the Super Sport category, with a
'tech-speed' of just 165mph.  Prior to the actual run at speed, they have a
practice session over a shorter section of highway, about 6 miles, where you
are allowed to test your equipment out and make sure all is right.
  I had a different navigator onboard this time,  who was unfamiliar with
the drill and forgot, during one of our 'passes' to raise his window...So as
we approached about 160mph, the gps balked and wouldn't go up...I am
checking all the gauges, the readouts, etc..wondering what happened to the
power,,then it flashes that the window is down...Well, at that speed, you
can't raise a window...it'll be blown right out...so we finished our run at
about 163..max..The return trip, we up all the windows and ran at an easy
175...and got chastised for exceeding our Tech Speed..
  Running at those speeds demands all the mirrors off, tape on all the body
panel joints, un-hooked sway bars, an excellent alignment and some big
cojones, especially for the navigator, who has to read the route to the
driver and watch the mile markers blur past..
  Don Hanson