99 Firebird door panel

My Firebird is developing a small crack in the door panel. Started out looking like a scratch when I bought the car a couple years, but is now about 2 inches long and separating. Where is a good place to look for a new replacement panel? This crack starts from the window molding and runs straight down. Is there any epoxy to repair this?

This problem is created by a wonderful GM design that allows NO flex. So it eventually cracks.

I searched LS1tech and LS1 for the fix....but was unlucky. If I run across it, I will post it.

I have this same situation on my 2000 T/A , on both doors . About a foot from the latch end at the top . Anyone else have the rear panels that will not stay attached ? The dealership put screws thru mine to hold them in place . Rob