No, this is not the whine under acceleration many of you have witnessed. With 7k miles on my Model S, I now have a squeal from the rear of the vehicle which started out very subtle and is now quite loud. It occurs only at 25 to 40 mph and disappears with even the slightest acceleration of slightest deceleration. Meaning that the tiniest positive or negative load stops the noise. This rules out brakes and leads me to the motor bearings, ring and pinion or pinion gear bearing (I'm a pro mechanic and fairly accurate with diagnosis) except that all these bearings are in a lubricant and this has a "dry" sound. I suppose the inverter would be possible but this noise is only under zero load. It did get noticeably worse with 4.5 update. I have spoken to service but they want to hear the sound for themselves. Maybe I'll find time next week to drive the hour to service. I searched the forum and found nothing. Has anyone else experienced the same symptoms?