You're entirely welcome speed!

This may be a temporary install as I sorta want to do all dark tint glass in the rear. Already had the truck broken into once, and several toolboxes stolen, so preferring to stop the felonious Looky-Lou's from peeking in. Main thing that po'd me about the break-in wasn't the tools, but how they used a pipe wrench to crank off the perfect original rear handle!

I did notice the second window seems to bulge outward to rear of truck just a bit. On that one I cut the gasket even longer, to eliminate any gap or leak where the 2 ends butt up at bottom. That may not be such a good idea, maybe a guy [or gal, Jill] wants to cut to the minimum to close the gap? Seems likely that a bit too much gasket material is what causes the window to bulge or stand proud of the opening.

I won't know for sure until I re-install, but I can't see any other explanation, especially when the two windows came out different according to length of gasket. Shorter gasket, less bulge, longer gasket [more fill in opening] more bulge.

Looks like a handy tool for install would be a chromed shaft screwdriver, 1/8" electrician's blade tip, about 9" or more long. Heat shaft and bend it into a 'L' shape about 3" from tip. Can't describe how it would work but self-explanatory once you started. Also instead or using a sharp prick punch a chromed shaft punch with tip rounded out would work well for sliding along slit in gasket at locking area, prying it out before locking. That was the hard part. This rubber is real soft & sorta sticky hence the chromed shaft recommendation.

I'm sure a dip into a soap lubricant would help the process but moreso if there's 2 people working to control glass etc. I would NOT lube the whole gasket before install, looks like a nightmare of control there! Just lube as you go, starting at bottom corners. A rubber mallet was used to move glass, but with lubricant just manhandling would do it.

Have fun!