1968 Barracuda Notch - Plano, TX

Plastic glass rivet was a challenge. The rivet is molded as one piece, the plug and the insert. You have to break the insert off the plug, then install it from the glass side. The OD of the insert is considerably larger than the hole, so the interference once you push it in should hold it pretty tight. The attached picture shows the two pieces as sold, molded as one piece next to the old one that I took out.

Pushed in from this side. No way you can push it in from the other side... which is effectively what I was trying to do yesterday. The interference is significant, I had to use the big channel locks to push this in.

Posted a question on Moparts and someone named "minivan" helped me figure it out.