All I can say is that I was holding off for better information on the subject and just quit waiting. Ordered steel wheels with Pirelli Winter Carving tires from Tire Rack. They sent the shipment confirmation within five hours so I'll know soon. I figure it can't be a disaster or Tire Rack wouldn't sell them and someone would already have reported that it doesn't work already. I'll write in when I get them on my wife's Mz5 ("Cinco").
Also I can add that I've never bought winter/snow tires in my life but the stock Toyos are the most awful tires I've ever experienced in the wet, snow, and ice. I might put up with them myself but couldn't let my family use them in the winter, even mild winters like we get here in Minneapolis.
Jon