Door card / trim.
Did the same for left and right. Similar theme. dampen anything that squeaked or rattled.
Peel back factory felt
The factory BOSE grill was sqeaky as heck. Each heat staked rivet was loose. I covered everything I could in butyl rope to dampen vibration. The end result was pure silence when you press on the speaker grill. Far better than the squeaky mess it was.
Large open flat surfaces like the back of the cup holders resonate like mad when bass is playing. So, I dampened them up too.
Since the midrange is mounted to the door trim panel I wanted to dampen the region surrounding it too. With midrange blaring I am sure the trim resonates along with it. So, tame it down.
Go throughout the door trim panel and secure loose wires.
Totally deaden the air space around the midrange and try to isolate it from midbass.
Put felt back and prepare to re-install:
Ge0