I'm looking at a 2006 Mini here in Italy. It has 100k us miles. The owner says a couple months back it started overheating so he took it into the shop where they milled the head, new head gasket and replaced two pistons. He states hes been driving it since with no issues. I can understand the head work and the gasket is a no brainer. It's the two pistons being replaced that has me dumbfounded. The engine sounds solid and it drives well. Any thoughts?