Hi all, My 2017 MS 75D is a little bit short of 2 weeks since pick up. A few days ago I was driving on the freeway and then back through town and noticed a loud noise coming from the back. Was tough to hear at first because I had music on, but when the volume lowered for the nav after the freeway, I noticed it. The sound was loudest at higher speed and went away when slowing down. When it was at it's loudest, it was loud enough that it gave me a head ache. Unfortunately I don't know exactly when it started or what speeds caused it. It has since gone away and hasn't come back. My question to everyone, any idea what may be causing this? I did some reading and it sounds like this is related to the drive train. I'm really hoping that I don't have a bad unit on a new car. Any help is appreciated. Thanks!