winter tires is a must. esp since the m3s dont even come with all seasons from the factory. summer rated ps2s are very bad in winter or cold weather conditions.
i have a set of sottozeros for winter.
Current: 2013 F10 M5 & 2013 GLK350
997.1 GT3RS (gone)
2009 WRX STI (gone)
e92 M3 (gone)