[overcoil]

Brake dust yes but that squealing unusual unless your getting the pads very hot and doing repeated hard stops from 130+ down to 0.

I wonder if they really replaced pads and if they used brake pad back side anti-vibration paste.

I had a new Benz took it in for brake squeal they told me they looked at it and when the noise continued did the brake work myself and found a pad that had fallen out of the slider channel - that was Mercedes of silver spring and they did shoddy work.