Bought a 2004 CTS brand new and have put 4 sets of tires on it. It came with goodyears, then we went to michelin, then yokahoma, and now we have nokian. We have had a road noise since the 2nd rotation of the first set of tires. Always after the 2nd rotation of any set of tires the noise continues. We have had the car aligned 3 times also. We will not buy another CTS due to this problem.