Mine was creaking at the beginning of winter, closed the cover seem to silence the creak, perhaps tighten things up. I guess the real test is on a really cold day say -20 degree Celsius.
Some say Gummi-Pflege works.
http://www.autosol.com/ProductDetail...oductCode=6501
I have a rattle in the boot that preoccupies my attention. I read the theards on that. Next month I will try the dealer, then try to adjusts the posts on the rear door, as per that thread.