Has anyone had their tires get indentations on the outside surface of them? All four of my tires have this irregularity. Just yesterday I went back to a national major car repair center and asked them to check out my tires for defects under the warranty. I figured I would be covered as the two front tires only had about 5,000miles on them and the two back tires have about 10,000 miles on them (all are the same size). The tech guys said they were not defective and I was free to go on my way. Of course I was not satisfied, especially since these indentations are quite noticeable and go all the way across the outside surface of the tire. Believing this to be a safetly issue, I argued for replacement under the warranty. The manager told me the indentations were due to the area where the two pieces of rubber (the seam) came together and that they were not defective. I continued to ask him to put his explanation in writing. He kept refusing and then denied he even said the indentations were due to the pieces of rubber seamed together! After going a few more rounds with him, all of a sudden, he said, “ok, I’ll replace just the two front tires - no charge.” After thanking him, getting them replaced, and going on my way, both my husband and I are now left wondering if the two back tires need to be replaced (under warranty as I believe they are defective) and if they are safe to drive on - especially at high speeds on the freeway. In all our combined years - over 90! -of driving and owing cars and trucks, we have NEVER had tires do this. Has anyone out there experienced this problem with their tires? Any and all advice and feedback is welcome!