Convertible windshield trim

Anyone know how the bottom piece of lock strip trim is attached on the bottom of windshield on a 68 dart convertible? My buddy just had his windshield installed today on his 68 GTS droptop, and the guy installing the windshield say's he thinks you would use some kind of bedding coumpound on the bottom of the windshield seeing the is no lower channel like a hardtop. Any help from you convertible guy's would be awesome, Thanks Jeff