plastic piece rear quarter window

This is needed for a 67 dodge dart.

What I need is the plastic piece that fits in the slot on the rear quarter window metal trim. The rear most hole in the metal trim has a plastic piece that spreads when the screw is installed also holds the metal piece away about 1/2 inch. Sorry I do not now what this is called. I Just need one, let me know who might have one, used, new It doesn't matter.
Shipping to 76148.
Thanks