Replaced ANOTHER tire now, makes it both front AND rr tires with bad ply separations. I can already feel the lr tire is next. Major quality problems with these tires make by Cooper tire! Tires came on my 300sd I bought a couple months ago, previous owner died, one of the few receipts I don't have is for the tires. Basically the tires work fine then a vibration starts and quickly gets worse over a couple days. Good faith replacement? I don't think I want them on any car I own!