Anecdotal comment:  I had a Chevy pickup with a chrome glove box door that
had a small dent in the face.  Sunlight coming in through the rear window
reflected off the glove box door onto the seat.  That small dent created a
(roughly) parabolic reflector that created a 6 inch line of what looked like
cigarette burns in the cloth seat upholstery.

Obligatory Vanagon content:  It would probably work about the same way in a
Vanagon :-)

Mike Snow
Camp Pendleton, California
1982 Westfalia 1.6TD
1983 ASI 1.6D

<snip>

>I have been using a foil-reflecting sunshade in my Vanagon.  I have >just
noticed that the
>backside of the visor has been burned in several places.  Kind of like >the
magnifying glass
>effect.  Fortunately it did not catch fire.
>If you are using one, check to see if yours is causing damage.
>
I fail to see how this is possible. Does the shade not fit under the
visor? Mine does, so its impossible for the back of the visor to be
affected. Or, do you mean the front of the visor? I dont see how that
could be affected either except possibly by sun emanating from inside
the vehicle.