Private party, trade in, whichever....you are buying a used car and have no idea how those miles were put on. Go look at the Forced Induction section of Corvetteforum. You will see plenty of guys putting the stock cam, exhaust, shifters, tires,...back on their cars and selling the high performance parts in the parts for sale section. I bought my first blower from a guy like that. I'm sure the second owner of his car was amazed at what great shape his stock tires were in. The pair of slicks he never saw, well good thing he didn't see them. In '03 I almost made the mistake myself until someone PMed me that the low mileage Vette I was asking about had seen many 1/4 mile passes and was only stock for a little while, and then again when I was considering buying it. I've seen threads dedicated to how to remove the rubber from the back wheel wells. Low miles sometimes = 1/4 mile at a time.