Rear door wind noise above 70 mph

Any info would be appreciated. It sounds like a rattling on metal, and inside the door. Almost constant over 80 mph. I have removed sound plastic , and taped down all wires. Dont know if its inside the door (sounds like it is)or exterior fender flare possibly. I have changed the lower corner seal but not the main door seal, which doesn't show any irregularities. I've been able to mimic the noise by strumming an inner door rail guide I assume is for the glass that is rubber. This takes s good amount of force. Also by manipulation of the outer fender flare attached th the door, this also takes a good amount of force. My next move is blowing air around the door seals and trying to pin point, but to this point and lots of time and thought, nothing else really seems loose and I'm stumped.

 

Tough one. Just for grins check the rock shields on the brakes to make sure they are not too close to rotors.

 

You could try to install some sound deadening material to the inside of the door under the door panel.