A few years ago I read a thread or two on the parking brake mechanism teeth wearing down and that replacing the part(s) was a bitch. I've never heard of this happening before, what in the world is BMW making these parts out of?? Maybe it's occurring more in Europe where people often engage the parking brake when stopped at traffic lights? Who knows. Since reading those posts I always push and hold the release button down when pulling up on the parking brake. But really, it's ridiculous.
Here's one thread I found:
https://z4-forum.com/forum/viewtopic.php?t=93188