Ever since manufacturers had to go from asbestos to semi-metallic pads, squeal has been more of a problem (metal -to-metal contact, DUH).

I had a mechanic friend of mine that would cure the problem by making cross-hatched cuts across the pads. Might be worth a try...

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car