I'm reposting this from the M4 Maintenance forum because I just read it and it's something you never think about. I didn't want anyone here to have to deal with a $2 dollar air freshener causing hundreds of dollars of damage to vents. Just took mine out of my brand new 540i.
Center AC Vent trim
https://f80.bimmerpost.com/forums/sh....php?t=1422629