[len_eng]

I have a 2018 2SS that started warping rotors at 55,000 miles. The dealer turned the rotors and balanced the tires. Several weeks later the shaking was back and I was told that I needed new brakes. $1500 out the door and several weeks later vibration is back. Once again they turned the rotors and then they blamed the snow tire/ rim combination that I had been using during the winter for the last two years (with no adverse effects ). I took the car home and put on the factory summer tires with the factory rims. Several weeks later the vibration while braking is back. The dealer replaced the front rotors. Several weeks ago the vibration was back, this time I took the car to my mechanic, who turned the rotors and told me that there was crap behind the rotors on the mounting surface and the wheels were not torques properly. Well here we are two weeks later and once again the brakes are vibrating when I apply them above 65 mph. Any recommendations? This will be traded in on a V6 (my last two were fifth generation vehicles both of whose brakes lasted for 80,000 miles plus). (oh yes and through another dealer )