I've noticed something comparing my glass T Tops to my Lexan T Tops that is making me think that perhaps over many years, Lexan is more likely than glass to leak. I have all new GM weatherstripping on my car, and a brand new T center bar. The arc of the glass T Top is more agressive than the arc of the T Top bar section that it comes in contact with. Here is an illustration of what I mean:



This causes the front and rear edges of the T Top be be pressed harder against the weatherstripping. Over time, glass will not warp, keeping this pressure. I never saw lexan tops come right off the line, but I would assume that when they were new they would press just as the glass would. Is it possible that over time, Lexan can warp and form to follow the shape of the T bar perfectly causing less vertical pressure to be exerted on the weatherstripping at the front and rear of the T Top than what was originally there?

 

Interesting observations.

But when I replaced all my weatherstripping this past summer, I also swapped over to glass t-tops. They do fit nice and tight, but still leak!