Yep, lots of E36 interiors are in rough shape. Thankfully previous owner took great care of it and mine still looks great. *knock on wood*
Do a quick google search "E36 glovebox" you will see lots of "sag". Even google has the suggestion " E36 sagging globe box".
Headliners, door panel/door panels cards can peel/sag, and other small issues.
I'm sure E39 interiors are better but from what I've seen the seats seem to look worn out compared to their age.
But I still love BMWs.