this is my reaction to reading about the traffic light "shakes"
because of a similar rough idle on my 300SE - I started a long journey..
Gradually replacing the OVP , fuel filter & pump, spark plugs & wires. Then the Distributer cap & rotor. I Changed out the motor mounts and cleaned the Idle control valve(replaced both hoses on it). The rough idle was almost gone.
Finally a couple weeks ago I got around to replacing the injectors and hoped that was going to be it. I had the mixture adjusted at the shop and drove away feeling real good. ...
TWO WEEKS and I can feel that familiar shake (just a bit) skip & hesitation returning - when coming to a stop...and the mixture is quite rich I think, because when pressing on the Air Flow Sensor Plate the car dies instantly and gas milage is down. The Inside of the above was moist (leaking distributer ? ) to the touch.
Maybe this info can assist you in your quest to cure the shake...and hopefully someone else might have advice for me too.