[MikeT]

I have the factory roof rack. When installed it I noticed the same noise as you have described. I tried the same things you have including some others. What I did to boid the noise was to remove the headliner and installed Dynamat (If I got the spelling wrong forgive me) sound deadening mats and installed them on the roof skin. The cleared 95% of the noise. To clear the remaining 5%, I removed the crossbars.

The way I came to the conclusion to try Dynamat was that I noticed the the roof skin on the Ridge is quite pliable (Soft and easily bowed by lightly pushing on it). I ended up tapeing four six pound soft wights (Scuba stuff) to the roof in the area aroung where the front crossbar (or the sunroof would be) and back by the back crossbar. This had the same effect as the dynamat. Try weighting down these areas securely and take a test drive and let me know what your results are. Good luck.