I too am experiencing rattling noises from both front doors...actually sounds like it is coming from the windows. I also am experiencing the "helicopter engine noise" that I agree is irritating! Some other issues and concerns are:

1) White strings coming out from the doors and seats

2) Fender guard trim peeling off

3) Rattle coming from upper driver's side dashboard that I have gotten fixed, but it came back.

I haven't had the time to take my car back to the dealer for the above problems...eventually I will...however besides these minor problems, I absolutely love the car. My family has 2 Mercedes, an 01 S55 AMG, and a 99 ML320. 2 Lexus, 98 LS400, 00 RX300 and my car doesn't feel the least bit inferior...(ok...well maybe to the S55)