I have felt that in mine as well on one occasion recently. I do not think it is a problem but if it occurs more often I will report it to the dealer at the next oil change.
Every so often, and only when turning left at a very slow speed, just for a spilt second there is a high frequency buzz that I can feel through the steering wheel. It makes no sense but I can only assume that it has something to do with the power steering. Does this sound familiar to anyone? I have driven a lot of vehicles in my life and this is a new one for me.
I should also mention that the high frequency vibration (100Hz+) is also accompanied by a high pitch sound as well. I also don't have to be moving to feel it. It can occur just when I turn the steering wheel stopped just beginning to make a left hand turn. It never occurs while the wheels are pointed forward or to the right. I have reported it to my dealer and if it gets progressively worse, I will see if they can duplicate the issue during a test drive.
I park in a multilevel parking garage at work where you keep driving in circles to go up or down levels. When driving through there slowly and making those turns, I can feel this buzz in the steering wheel. I'm not concerned about it, seems like just a characteristic of the power steering system or something. Of course if it gets worse or worrisome I will report it. Haven't noticed any particular noise.