Welcome to AF.
Just in case you should include the year and model of your Grand Prix. From the Pic #1, I am assuming '97 - '03.
Can you point out specifically the moulding you need? Hard to tell by the pics.
As far as the rear quarter window trim this is what I have:
Moulding, Rear Reveal - Black Right - PN: 10441918
The moulding piece at the top of the right rear passenger door is:
Moulding, Upper, Reveal - Black Right - PN: 10436587
We have some GM parts guys so they may weigh-in to help out and provide better info.