Just got my car back from the dealer. I made sure to drive until the "whistle" started before I took it back to the service department and I also brought a copy of this thread! The mechanic heard the noise as soon as he reached 40 MPH. They actually put the car up on a lift and had someone "drive" to recreate the sound while someone was underneath the car with a stethoscope ��. They were able to find exactly where it was coming from. They just had to lubricate the left axle shaft seal and the noise disappeared!
Nice n easy, thanks for following up. Things like that will probably repeat with others.