Recently I had to send back for credit 4 tires I purchased from Tire Rack in 01, they were Yokohama AVS DB's, when my wife had her car serviced our mechanic said all the tires had dry rot, I looked at them and between all the treads on each tire there were cracks 360 around. I called tire rack, and the sales person told me there are a few things that could happen, Sun and UV, sitting on hot pavement a long time, enviromental factors, etc. I ordered 4 new tires and sent the old ones back, got a $134 credit plus shipping. The Tire rack people told me not to use tire dressing as they dry out tires and could cause dry rot, they said to get a good vinyl rubber clearner and that's it. What do you folks think? Thanks and have a great weekend, wherever you are!