Well during a previous mod i had cut out the entire back window of my Mustang. I got sick of the gaping whole and wanted to *fill* it in somehow.
This is my story...
So i have this black sports tape from my hockey days, it has more of a fiberglass kinda texture then electrical tape does.
I cut the tape just slightly larger then the hole that was my window.
Then i put a thin layer of Elmer's Glue all over it and let it dry...well whaty do you know it drys clear plus *soaks* into the tape a bit making it stiffer, so i then did the same thing to the other side...note: too much glue and it won't all dry away clear.
i then put in into the window space from underneath and then just glued some more around the edges so its nice and secure.
so then you have one fake "fiberglass" window replacment.
p.s. sorry for the blurry pictures.