Interior Window/upholstery fastener

I have a 2000 Grand Prix GT with leather interior. There are 4 "devices" that I believe clamp down the leather door panel. They are located on top of the door between the leather door panel and the glass (bottom part of glass) but does not touch glass. These are about 15 inches or so long and are U shaped and I believe they are made of metal and are powder coated or plastic coated. They seem to small sharp teeth inside the U channel. I have 2 or three that have become detached and have broken in half (that is how I know they are made of metal).

Does anyone know the official name of these (I want to call the dealer to see if they stock these). Or does anyone know if there is a place where I can buy them for less than I would pay at a dealer (ebay?)?

Try gmpartsdirect.com or rockauto.com and search the collision section. You should be able to find the part you need there or at least get the name of what it is called. They also sell genuine GM parts for less than most dealers.