Rear Window Angst.

[Perfectlap]

don't do the chop in the winter/fall without first heating up the cockpit.
I think even if you have a glass window you should let the canvas warm up a bit before pulling and stretching the canvas. The bows under the canvas will crease and wear away the canvas when its cold.

For the those lines across the plastic window use Renovo clear plastic polish with a high speed polisher or electric screwdriver polishing attachment. Clean it weekly with Plexus. And of course don't get any soap on your canvas. Canvas cleaner only.