[TJ Clark]

The solution was to remove a small amount of fiberglass from the opening.

The folks who made the first attempts did not truly understand the situation, so in an effort to get the glass to sit further back into the coach, they removed material along the A pillar. Several times.

The real solution was to remove material along the long horizontal runs at the bottom and top of the opening.

I am not saying this is your problem, but “new gasket” and “difficult to install” raised my eyebrows to the possibility.

Thanks for your reply. 

They do sound suspiciously similar. 

What amount do you suspect was needed to be removed? Do you expect this to be a long term fix, or will is just stay in longer between events?