The "double roof" on the land rover is called a safari roof.  It is
basically another sheet of aluminium (aluminum) about 1/2-1" above the roof,
mounted on the ribs.  I can't see how this would affect crosswind stability.

Here, (Australia) we have temps that occasionaly hit 120F, with extended
periods over 100F, so this is an issue.  The landie roof really only works
while there is airflow.  I would like a system that provides passive
insulation at all times.  I like the idea of basically a roof rack that
extends over the windshield and is comprised of either solid heat reflecting
material, or expanded mesh similar to that seen on metal stairways.  Being
able to remove the rack in the more temperate months (about 3 here) would be
advantageous.  To me, the extra windage/crosswind problems would be
outweighed by the thermal comfort.  Having an overhang would be a bonus as
far as shade was concerned.  I have seen interior temperatures in parked
cars exceed 150F, so this can only be beneficial.

Andrew
(who complains when it gets over 70F - anyone have IT work in Alaska?)

----- Original Message -----
From: "Ben T" <BenTbtstr8@AOL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, October 04, 2002 4:05 AM
Subject: Re: Double Roof / Portable Shade

> In a message dated 10/3/02 10:04:08 AM Pacific Daylight Time,
> pokey@VANAGON.ORG writes:
>
> << And started to think about that full length roof rack. I have
>  seen quite a few Land Rovers with double roofs in order to
>  stop the sun from beating down directly onto the vehicle's >>
>
> It would be interesting to see what such an arrangement will do to your
> crosswind resistance and other aerodynamic complications. Probably great
in
> the slow rough stuff but a liability on the tarmac.
>
> BenT
> <A HREF="http://hometown.aol.com/bentbtstr8/myhomepage/index.html">Vanagon
> Cafe</A>
>