Detroit Muscle Technologies has high quality products, and you can find high quality seals here too.
www.steelerubber.com
The cars with frames around the door glass, like sedans, are glued (3M Super weatherstrip adhesive) or just pop into place, no fasteners. If you are referring to the door seal ends, which help seal the door glass at the ENDS of the door seals, they are held in place by screws that are usually supplied with the seals. The rest of the door seals (around the perimeter of the door) are held in place by little plastic clips, mostly white in color. If you mean the ones at the top of the door that seal the door glass from rain & debris from entering the top part of the door & clean the glass somewhat, called "cat whiskers" or window sweeps, they are usually held in place with metal clips that slide down the into slots in the top inner flanges of the door. Hope this helps somewhat.
