JR RX8

For the last few months I have been hearing this weird squeaking/rattling or rubbing sound coming from the right rear seat/speaker panels ?? This only happens when I hit a bump or go over something that might make the body twist or torque. At first I thought it was the rear windscreen about to come loose. Then I thought the panels on top of the seats that house the speakers, so I stuffed some foam cord between them and the windscreen. Still there. Even odder is if I leave the car outside in the cold for a few hours and then drive it, there is no sound . But if its warm ( like inside the garage) or outside and I drive I hear it every time I hit a good bump or small pothole or something that might make the car twist. It's only on the right side and it's definitely inside the cabin. It's also driving me batty! I looked at the TSBs and thought I saw something there but it did not accurately describe what I am experiencing. Anyone with ANY ideas greatly appreciated!
Thanks