I just got my M back from a service appointment (reprogram CA keys) so it was nice and clean in the snow near my home. Unfortunately, I haven't figured out a winter setup yet so I'm still on stock 19's with summer tires(!). So today it's resting in the garage while we take out the wagon (535xiT).
In case anyone wonders how summer tires perform in winter... my driveway is about a .005% slope and I almost didn't make it into my garage! The compound gets so hard below freezing that it slips like crazy even on dry pavement. I can't wait to get a winter setup going so I can start DRIVING again!