I got caught in a major snow storm in West Virginia last year in my Boxster. I knew it was risky to be out because I knew my tires were bad, but the weather was good when I left Virginia and I thought the weather would hold. It was quite an experience, my rear tires were almost completely gone. Lots of slipping and engaging the traction control. I now use a dedicated set of all weather Falkens in the winter with lots of tread....
Ed