[rjc32000]

Just got M sport back from dealer. Took it in for squealing brakes at low speed and recurrent false "windshield wiper fluid low" warnings at cold temp. This was actually 2nd time I took it in for the brake issue; the first time BMW service more or less blew me off and reported they could not reproduce and that brakes were within spec. This time, I made a half dozen or so short movies of the brake squeal with my iPhone and showed them to service manager. Picked the car up Friday afternoon. They removed brake pads and rotors and chamfered the surfaces (whatever that is). They also updated FEM and Nav while it was in the bay.
Service diagnosed the washer fluid light error as being caused by a faulty sensor, and they have new part on order.
So far, so good. Brakes are quiet, and hopefully the silence will last. I'll keep everyone posted on the washer fluid issue once the part is installed, and let you all know if the brake squealing returns.

Happy new year!