I just bought a 2007 Cayman 2.7 with 26k miles. The rear tire tread depth was at 2.8mm left and 2.2mm right (fronts at 6mm and 5.5mm). When I finally drove the car, 860 miles worth to home, I was a bit surprised at the noise level. I knew I would be replacing the rears and did so yesterday with exactly the same RE050A's. I had my fingers crossed that they would be better because I didn't want to commit to a different brand. They are much much better but there is no doubt that some noise remains. As others have said, I think this comes with the territory. Also, as others have said, they are very sensitive to different road surfaces as far as noise is concerned. All in all, considering the good ratings/opinions on the Bridgestones, I consider the noise acceptable and a huge improvement over a worn tire. C.