Pics roughly in the order I progressed to reduce annoying rattles.
The iDrive I sprayed lube to stop the gears rattling.
The boot protector bracket broke, rattled, so fixed with carriage bolts.
Also make sure your seat is not touching the rear bulkhead.
Anything left lose on the seat or floor rattles, like specs. or keys.
Any rattle you hear at the front is probably from the rear.
Every gap around the glove box was sprayed with lube, hinges and stops.