Ya know, I've had several people get almost angry at their insistence that the coupe and fastback windows are different. They "guarantee" that they've measured them, and that there is some slight change. All I know is that in 1991 some a@@hole smashed the passenger window out of my '77 Cobra II and stole a bunch of stuff while I was in Spokane, WA for a Joe Satriani concert. I had a long cold drive back to Missoula, MT that night. The next day I went to a yard, and the best window I found that had factory tint was from a coupe. I installed it that afternoon, and it's still in the car to this day.