Somehow, my '01 M5's LCD screen rattles around at the top. Normally when you hit the cassette button, the screen folds down and stays down until you hit the button again, but mine will go to about 45 degrees, then reverse. Obviously something is wrong with it...but it won't sit perfectly flush at the top and that is where the rattle is coming from. If I hold my finger against the top edge of the screen and push towards the hood, it will stay quiet.
My thinking was to somehow cut power to the car just when the screen is at 45 degrees, place a few small felt pieces back there, and then let it close again, but it's going to be difficult to do.