Just to close the loop on this thread, I broke down and bought a dial gauge, pulled the front wheels and measured the front rotors. Both front rotors had runout, the left worse than the right. (LF 0.005", RF 0.003") I got 2 new BMW OE rotors and pads/sensors installed and the shimmy is gone. I guess I'll have to wait to see if it comes back, but at least I now I guess I have a 2 year warranty on my new brake parts. I forgot how good the initial bite on OE BMW brakes are, its kind of nice.
Last edited by asus389; 02-15-2013 at 02:53 AM.