We went riding at Dirt Nasty in Morehead KY yesterday afternoon. There were lots of steep grades down which required a lot of braking. After about an hour of driving, we headed back to the parking area to switch off and let my wife drive. We immediately headed down a hill and heard a strange rubbing sound coming from the left rear. It only did it for a second or 2 but it was obvious. When we got to the bottom, I checked for anything stuck or binding - nothing in tires, wheel wells clear, rotors turning smoothly etc. Even had her drive it back and forth to try to see anything. We kept on riding for another hour and a half or so. It did not come back until the last 15 minutes and again just on occasion. With only 200 or so miles on the car would not think it's the belt but that was the only thing we could come up with. Anyway, going to pull the cover when I change the oil, but wondered if anyone had other suggestions on things to check or if anyone else has experienced this. Thanks y'all.