Stuttgarten

I've got some noise coming out of driver's door panel that's driving me nuts. It's been going on for over a month and it feels like it's not going away. It's very hard to pin point exact location, but it feels like it's coming from where seat position buttons or that general area. Of course it happens when car is moving, but what's more interesting is that it even occurs when you have a vibrating noise nearby and my car is off. Like more than once, I'd be parked and a another car passes by with a "bad muffler" and right away the noise would occur, a buzzing type, which tells me something is loose inside door panel. It is not related to sound system as it happens even when car is turned off, as I just explained. What could be loose in there?

I've watched a couple of you tube videos on how to take that door panel off, but looks like everything in there is held pretty tight.