Chris,
Give Tirerack a buzz. They will hook you up with a good "winter" setup. It wont be as cosmetically pretty but it will get you through the foul weather and be resistant to the abuse of winter. (heat cycyling, massive heat contrast of the snow vs hot brakes, salt, etc) http://www.tirerack.com Tell them MercedesShop sent ya...

Hope that does the trick for ya...Lee