As I drove the car home from the dealership, as I approached 50mph, I noticed a constant whistling sound that was coming from outside as rolling down the window definitely made it louder! It is loud enough that it can be heard over the stereo playing at a comfortable volume! Terribly annoying. It sounds like I have installed deer whistles! Took it back to the service department to be told that they didn't hear anything. Sorry. How can "German engineering" allow this to happen? I'm pissed!