Kinda funny this was brought up. I am bringing our 08 ML350 in tomorrow for it's 1000 mile checkup and was gonna have them look into a creeking sound coming from the passenger's side front windshield area, about a foot and a half from the right side pillar, right where the windshield meets the dash.
However, this only seems to occur in colder weather(below about 40F) and does get annoying, at times and never goes away, once it starts. HOWEVER, with the weather being 60F today and again tomorrow, it didn't happen today and probably won't tomorrow. So I doubt they will be able to find anything.