Red,
On the back window gasket try this ..put the gasket on the glass use some twine in the groove that goes against the cab and ty it on the glass, then put lottsa blue painters tape around the perimeter to hold it in place real good an set it out in the sun that should help get it to conform to the shape it needs to maintain especially on the corners wich will make the install a little easier....I understand your frustration ...makin a straight pc of window gasket go around the corner and stay there is nerve rackin at best~!
Being you are in FL. you should have SUN...it hasnt made it to PA yet!
Hope this helps.
Tim