I was in autozone yesterday getting a part for my vette and asked the guy about a powermaster unit for the turbo buick. He told me that they no longer carry them. I bought mine there many years ago under a lifetime warranty. The parts guy was of no help. If i need another one is my warranty cancelled? Should they refund my original purchase price? Or did the guy not know what he was doing. In his defense he was a fairly new employee and all he co-workers were outside smoking or gone at the time. I have a couple of cores in the garage, do they have any value? Thanks.