I just bought a new 2020 CX-5 Touring with the preferred package about a month ago. We love everything about it so far, but yesterday, my son and I were going over some bumpy downtown streets at about 15 or 20 mph, and we heard this rattle that seems to be coming from the right rear. We were riding with the windows down. I rolled them up, and we couldn't hear it. It was not constant, just when we hit some of the bumps. it sounds like a loose piece of metal that vibrates when you hit a bump. I checked the mounting brackets for the roof rails and they seem secure. I have checked everything that seems like it might be loose. Any suggestions?