I took out the whole shelf and c-pillars. I then used 1/4" or less foam tape and put on every part that might touch another piece of plastic, metal, wire, glass, etc. this got ride of the intermittent noises. However, I still had the constant creaking. I determined if you put something between the leather seat back and the rear shelf t stops. I bought really thick Air Conditioning foam that is about 3ft long by 4" wide. Works great and since it is dark gray you can't really see it from outside the rear window.
I love my car again!