My brake have made loud squealing noises since delivery of my GX 550 Overtrail. I have had my car about 3 months. I had similar issues with my 4Runner TRD Off-road with KDSS. The Toyota dealer eventually replaced my brake pads and the noises went away. My Lexus dealer has had my GX for over a week and are now replacing my entire brake system - pads, rotors, even my brake lines. I thought this was excessive, but I have not been told why they are doing a complete brake replacement. Lexus obviously knows more than they are telling me. Hopefully the parts will arrive soon and I will get my GX back and the noises will stop. My GX has approximately 2500 miles on it.