2017 cx5, purchased new in June 2018, only 16,000 miles. I park on the street in Chicago. 6 weeks ago we got 2 feet of snow. Didn't drive for a few days, but ever since I've had a terrible grinding sound from the front end. Only at low speeds when decelerating (with or without brakes applied) and when making sharp turns, worse in reverse. Thinking it was just oxidation, I've tried hard braking, multiple brake pumping, even an under carriage car wash, nothing fixes it. I can't imagine a car with 16,000 miles and less than 3 years on the road would have rotor or pad issues. Any thoughts?