https://f87.bimmerpost.com/forums/at...1&d=1600986769
Yes, I mean the metal panels you order to fill in the holes beside the rear seats. It’s an oddly shaped panel, so I’m wondering if something fits in that space or if the engineers made it concave to change the resonant frequencies.
My M2 has not been pulled apart yet, so I can’t physically see what’s there. Filling this hole with MLV and/or CLD and applying bonded acoustic cotton and/or hydrophobic melamine foam to the cavity behind it should reduce noise there materially.
Another comment: many here are ordering the rear sound insulating panels. It looks like the insulation there is typical BMW ~3/4” acoustic cotton with a compressed scrim layer for maintaining shape. Have any of you simply made your own insulating panel with a sheet of 1” acoustic cotton? Or a combination of MLV and an absorber?