I only noticed this because I had a factory defect where my left rear brake squealed when applied (with the brake pedal). When making left (only left brake had squealing defect) turns beyond a certain steering angle I would also hear the brake noise. My guess is that Tesla is applying inside rear brake to assist with turning. Interestingly, I could hear this at highway speeds on sharper left hand turns, not just at low speeds or aggressive driving. Has anyone else noticed this? It can't be good for efficiency to drag the brakes when going around turns where traction control is certainly not necessary. Maybe they are achieving the cornering performance that people rave about because they are literally pushing the car around the corner with the outside rear wheel receiving extra power.