The power steering motor. The electric power steering functions by turning the steering wheel using a gear and motor assembly attached to the steering column. It determines how much to turn the wheel by a torque sensor also in the column. When it senses you putting torque on the steering wheel to turn, it will assist you in turning the wheel. That is why AutoPark in Japan is possible, as well as VSC possibly countering your poor steering attempts.
But it isn't all the time. It was really bad 3 weeks ago and the Factory Rep. from Toyota was at the dealership 2 weeks ago. I had him drove it. I couldn't beleive it there wasn't a rubbing sound from the wheels,wheel area or steering and he did a 360 and backedup did corners all of the things where I would hear the rubbing noise and there was NO noise.
I told him You are sick until you get to the Doctord office.The service manager was in the back seat listening. So the rubbing noise I hear when turning the corners, backing up to park ishould not be heard. I have a Toyota Factory rep. and the dealership service manager to back me up when ccrnering backing up at low speed there should be NO noise from wheel area or steering. I there is there is a problem. I hear the rubbing again so when it gets more constant and louder I will go back to the Service Manager and let him ride with me to hear it so it can be fixed.
If your Service manager doubts my word I can verify it for him with the name of the factory rep. Let me know what happens with your rubbing sound. And what the problem was and the way it was fixed.