I personally have had good results with Pirelli PZero Nero M+S on my 335i in the DC area. Driven in light snow, no problem.
I am not sure if these tires are made in M3 sizes, but the Bridgestone Potenza RE960 AS do, and they have absolutely great reviews at Tirerack. Goodyear F1 Allseason are also available in stock sizes, but have worse reviews.
When the time comes later in the year, I'll go with the RE960 AS on stock wheels (or stock-sized wheels). That way I'm sure to get home no matter the weather, and won't be abusing the PS2 during the 2-3 months of cold weather.
Hope this link works: http://www.tirerack.com/tires/TireSe...ank=2&x=56&y=9