I agree with the others. The Pirelli Cinturano C7 that comes on the 35i standard, even though its marked "M+S", has a tread pattern that is not suitable for snow. In fact, the model itself is a summer tire, but Pirelli probably modified the compound a bit so it could be marketed as M+S for BMW. So even if you didn't get summer tires, the alternative is a summer-biased all-season.