I got my c230k 2 weeks ago and noticed that my buddy who bought his had different tires than I. He had z rated Michelins and I had w rated Continentals. The owners manual says that with the Evolution package I shoud have W's and the brochure says Z's. So I called the dealer and he told me to come in the next day and that they would get me new tires. And they did. And when my wife got home from the dealer with new tires there was some flowers waiting for her from the dealer congratulating us for our new Benz. We were pretty impressed!