I get this too after the car has been sitting for a while for the first couple stops. My rotors are only a few months old. Same with the brakes - they're wagner thermoquiet ceramics. Flushed the brakes recently too. Brakes are wearing evenly, but I still get a little grinding noise on the first couple stops when cold. Never really bothered me because it goes away fast, but I get it too. Mine don't squeal likes yours though. Maybe if you change the pads, that will go away.