GTS Plastic Top of Door Edge Window Guide

Does anyone have knowledge of this plastic piece that sits in the distal channel on the top of the door nearest the door jamb? It is only on the GTS, not the GT. Where can I purchase one for each side, they come as a pair.

 

Isuk, Thanks for the reply, I've talked to Alfredo at Dinoparts, their parts are for early cars? The US had an inside vertical flange on the part! The Parts Book is wrong, only the GTS had this part. I need to have it 3D printed? Don't know who does that.

 

Thanks, Leo!
Yes, the parts from Dinoparts are not correct.
I have also purchased them from Bill at GT Carparts. He is out of stock currently.