Don't know what it is called, but it is missing. Its the side piece that is outboard of the arm rest with the ash tray. black interior.

And yes, Im looking for one. Or at least the proper name or part number.

Firebird Central has them brand new. Frank's Pontiac parts may get them used. Upper rear side panels

Thank you sir. I will give them a try.

You are welcome. I just noticed you have the deluxe door panels. I 'm not sure how different the deluxe rear panels are from the regular ones. But the Firebird Central ones are for the deluxe. My rear panels were all loose in a box so I may be needing those too.