I had the rear window in and out many times as I final shaped the edges. I left 1/8 gap between canopy and rear window and have a small P weatherstrip laid down snug against rear window, allowing the canopy to press lightly against the base of the P and weathstrip it satisfactorily. Some say the leakage is necessary to ventilate the cabin. I say there is plenty of other leakage to release inside air. We'll see. If its a problem I'll just lay down a thin flat cushion instead. I don't think there will be a problem. Regarding the gap, I have noticed a 1/16 gap actually closed up on me during hot days outside so I chose 1/8 gap with the P seal. I like it.
Rear window callout is aluminum pull rivets. Did it.
Took awhile to clean the window. Rubbing alcohol worked great, then Dawn and water.