cableguy3 and HyundaiTech:
I currently experience the same sorts of noises from my '06 Sonata LX, from the front and rear dash/deck and windows. I may not hear it for a week or so. It's starting to get cooler here in NH, so this will be a test.
My general perception is ambient weather plays a role, because the creaking is not consistant. When I first purchased my car in February it was quite noisy. I can not source the exact cause, however, often times it sounds like it is generating from the frame, or where the windshield and rear window meet the body of the car.
-Matt