Top to windshield gaskets major squeak...
 

Almost unbearable. Major squeak since I cleaned under that flap. Now it's freezing.

Can I treat that gasket with something or slightly rough it up?? Or wax it?

gummi pflege. some also use vaseline as well
gummi pflege will condition the rubber

Is the squeak from where the top meets the rubber or from where the latches ar on each side

I had a slight squeak on one side and got some slick tape and put it on the finger that goes in to the receptacle. the squeak went away

something similar to this:
http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Products/~/Industrial-Adhesives-Tapes/Specialty-Tapes/UHMW-Tape?N=5472110&rt=c3

there is other stuff as well that will work