New X5 50i humming noise rear end - HELP!

[Btcus]

To the best of the best:

Right now I am extremely frustrated with my x5 that I JUST PICKED UP LAST NIGHT. It has less than 100 miles.

There is a high pitched humming noise coming from the rear of the car when I hit 40/50 mph. It's quite frustrating and I won't be able to keep the car if it can't be fixed. It does not go away when I put it into neutral.

I have 20" wheels, sport package, and adaptive drive if that helps with a diagnosis from the group.

I have called my BMW sales rep and they offered to look into it. My goal for this post is simple. I want to get a rundown of others who have read about or had the same issue and what their/your resolution/solution was.

This sucks big balls. Please help!

[jspdr]

Are your tires wear evenly? Sounds like a rear differential to me. If possible have it up on the lift and try to duplicate the noise.