After removing the glove box (see instructions in this Thread), on the right hand side you can see the back of the fuse housing and it’s associated wire bundle. The black housing doesn’t fit snugly into the white fuse frame, the small white clip that holds the black housing in is about 1/2mm too long which gives the black housing some play. This play then allows the wire bundle to slap the frame which causes the muffled rattle we hear. I just super glued the black fuse housing into the white frame and put a little extra glue between the wire bundle and the metal frame to keep that from ever moving again. Solved.

I didn’t try this, but you could probably just glue the fuse housing without taking out the glove box as a first step in diagnosing this rattle.