I'll call my dealer, as my 2019 320S is only a few months old. But- I figure if I've had this issue than others have had it too. there's a plastic trim strip that covers up the screw heads on the back of the trailer. No matter how many times I stick it back in there - it won't stay. So- I just permanently removed it.
does everyone else's just stay on? or- do people just throw it away?