Just replaced my roof rail weather-strips on my '87 Coupe. The seal attaches to the body from the base of the windshield post over the window and down to the top of the door. The seals are for a '87 Monte Carlo. I used Steele Rubber Products PN 82-0035-68 which includes both drivers and passenger door seals. Great product.

https://www.steelerubber.com/search?year=1987&make=chevrolet&model=monte-carlo&style=2-door-coupe

The seal fits into the runners in the rear and top without any glue needed. The seal comes with push clips instead of using screws on the rear bottom, my OEM seal used one screw but I am going to drill another small hole for the second push clip. The front of the seal is attached to the windshield post using double sided emblem tape. I cut off the bottom front of the seal to match the original.