I have an 86 T/A with the base spoiler.
I removed it to sand down and repaint and noticed it seems to be separating.
No coming apart, but there is a seam that has a slight gap.
I don't know if they are glued together or of there is something else holding it.
Don't see and visible fasteners.
Just don't want to go through all the work of repainting it and have it blow apart going down the road.

Firebird or TA Wrap Around spoiler????

Not wrap around, just the standard Firebird spoiler.

Mine separated at both the front and rear seams. Glued it back together.

Did you pry it apart and reglue?

Mine is not split wide open but there is a slight gap.

I was able to pry mine apart just enough to get some 3M structural adhesive in using an artist's spatula. Worked good, had to do one edge at a time as that adhesive has only about a 2 minute working time. No problems since

Cool, thanks for the tip.
I wasn't sure if I dared to try and pry it open or just leave it alone. I'll check it again to see how loose it is.