E46 Cabrio Rattle

Hey guys! So I've been hunting for a rattle that seems to be coming from the right rear of my E46. This is the best description I came across on M3Forum.

"there is a rattling sound coming from the vicinity of the rear window on the driver's side whenever I hit a bump or drive on roads that aren't smooth. Any time I hit a bump it sets off a short, fast rattle that is more of a series of vibration-like sounds than a clank. I've ridden in the back seat and unsuccessfully tried to locate the source. I've also opened the top part of the way (when not driving) to explore the mechanical parts of the top and cover to find a possible culprit. No success."

I've checked the exhaust mounts, heat shields, and back 2 rear sub-frame mounts under the car. I've also removed the back seats. I found a few loose nuts that secure the various trim pieces. I've tightened them but this particular rattle persists.

One of the posts suggests that a "pull rod" is loose. This part (no. 5):


Where is this thing? How do I find it?

in advance :-)