Another product that works well is Lexol

In June someone on this board suggested the use of the E6000 adhesive as a temporary fix for sealing the cracks to the rear window.
We had 1-2" cracks on both sides and at the bottom right corner. A storm was on its way and we needed something to tide us over until we can get around to putting on the new top.

It was a very wet Spring in New England and we never got around to replacing the top.
Well...four months later the hack is still holding. The stuff is pretty amazing...

If your rear plastic window is showing signs that it may crack...this stuff will let you get a bit more time out of it.
We are going to deal with the replacement next Spring, unless the seal continues to hold :-)

If you want to see the pics...here is the link:
[www.rainydaymagazine.com]

Click on any of the images for a larger version.

I did similar repairs on mine and they have held up without any issues for many months.

Lexel?

[www.sashco.com]

Although if someone comes up with transparent leather, Porsche might make it an option! Then Lexol could be used instead of Plexus.