Hello Michael and welcome to the forum. Trilliums I've seen use a product called Trimlok around the door frame. Basically it's a metal edge that clamps to the frame with a foam tube attached. It comes in different bulb sizes and channel widths. Do a Google search, you'll find the manufacturer. There was a fellow on EBay who sold
it by the foot. My 2010 Trillium
has one large bulb but I've seen earlier Trilliums use a smaller bulb and flat closed cell foam on the door.
The plastic strips for the headliner (which is most likely ensolite), is called T molding. It's my understanding it is no longer available. I have seen a product used to edge tables also called T molding. Perhaps that can be adapted? Do a site search for T molding to get some ideas. Good luck with your project. Raz