I have a 1990 tintop with similar side screens as you described, aluminum
frame, metallic screen, screwed on the outside, on top of the rubber seal.
None of my other vans has them.
as in this pics (not mine) -
https://www.thesamba.com/vw/forum/album_page.php?pic_id=1309221

but here's another weird thing... the 1990 tintop doesn't have rear hatch
wiper, there's a rear wiper on my 1985 tintop sunroof, all others have it.
I still wonder on those 2 options...

dan

On Wed, Sep 4, 2019 at 5:40 PM Richard Koerner <rjkinpb@sbcglobal.net>
wrote:

> A Westy just parked across the street from me.  As I have noticed from
> time to time, the Westy side window configuration is different from the
> Tintop configuration, presumably for enhanced ventilation while camping.
> For my Tintop, there is a legit 16.5 inches of open width...just measured
> with tape measure.  I'm trying to understand how VW determined to make this
> modification.  Seems pretty complicated to do so.  So....what is the open
> ventilation width on a Westy side window?
>
> Not that it matters much, but I made screens that attach to side windows
> with Home Depot stuff, and sheet metal screws that anchor into the rubber
> seal.  They have worked great for over 30 years.  But was curious about why
> the design difference?  I think Country Home Campers built and attached
> side screens exactly the same as me.  Maybe some minor differences on bug
> proofing at the sliding edges (for instance, I glued onto the edge of
> screen frame a specifically cut out edge of thin flexible plastic material
> to totally make mine bug proof, they match the sliding aluminum frame
> exactly; also used a bit of black foam rubber strip on interior perimeter
> for compliance); mine work great, but they are just normal screen material,
> gray fiberglass stuff, not the No-See-Um kind with super-fine woven mesh
> holes, although I could do this modification readily.
>
> Just fodder for discussion....but still curious.
>
> Rich
> San Diego
>