Sounds a bit safer. I had thought of this once but my two ideas for mounting were to hang, like the curtains, and somehow draw the bottom up to the glass at s better angle or use suction cups with hooks like you get at craft stores. 
I didn't like the first idea, but it seemed the easiest to fashion in a hurry, allowing me to maximize my usable options. (ie side & front windows as well, depending on how or where I was parked). 
The suction cups I thought should be tested for the weight. I'm certain something out there will be an available size that works.  I was only worried they would give and the panel would fall on something but still be in the sun. 
Roman

Sent from someone's plumbing

> On May 18, 2017, at 19:15, Neil2 <vidublu@GMAIL.COM> wrote:
> 
> Hmm.  I envision hanging them as close to the glass (doubling as curtains,
> fitting within the glass' dimensions) which I think would be plenty of
> venting around them.  I don't use curtains.  I plan to always ventilate the
> van when warranted.  Not thinking of the windscreen but first the hatch,
> then depending on results the two side windows in the rear.
> 
> Your turn.  :-)
> 
>> On Thu, May 18, 2017 at 3:13 PM, Roman Haag <romanhaag@ymail.com> wrote:
>> 
>> With what I've seen on the interwebs regarding overheating of flexible
>> panels when there isn't enough ventilation under them (ie directly mounted
>> the pop-top) I would be concerned about them catching the curtains or
>> dashboard carpet on fire.  Not sure its worth the risk to be inside a
>> vehicle in the sun, knowing how hot vehicles can get...(mostly due to news
>> related to pets and children being left in cars)
>> 
>> Roman
>> 
>> On May 18, 2017, at 5:30 PM, Neil2 <vidublu@GMAIL.COM> wrote:
>> 
>> I don't use my hatch glass for rear views and just realized a flexible
>> panel would quickly pay for itself if mounted inside, no?
>> 
>> I mean the angle's good in the mornings/afternoons and facing the sun with
>> it would be as simple as a tight 180 in the lot, so . . .
>> 
>> --
>> Neil2
>> '82 Diesel Westfalia (Ducky)
>> '86 Vanagon (SaVannah)
>> '08 170" 2500 Mega Roof Sprinter (Moby)
>> '90 Westfalia Subagon (SaL)
>> Fulltiming since August 2008
>> Nunquam Pendite Divendium
>> 
>> 
> 
> 
> --
> Neil2
> '82 Diesel Westfalia (Ducky)
> '86 Vanagon (SaVannah)
> '08 170" 2500 Mega Roof Sprinter (Moby)
> '90 Westfalia Subagon (SaL)
> Fulltiming since August 2008
> Nunquam Pendite Divendium