I did a sunroof similar to the one shown at the link you provided,
except I used a sailboat hatch and reversed the direction.  At moderate
speeds it brings in enough air flow to feel almost cool in hot weather.
At highway speeds I have to bring the leading lip just down to the level
of the front edge of the luggage area.

John Jensen
johnjensen@johnjensenartist.com
http://www.johnjensenartist.com
bluesbug@verizon.net

  Installed a sunroof in the luggage rack, and David Beierl still has it
on his website (it worked great!):
http://pws.prserv.net/synergy/Vanagon/sunroof.htm P