I've got a nice combination working right quite well right now. I went to homedepot and bought three bags of tube sand (picture: 4in diameter x 3ft long bag, filled with 50lbs of sand) and placed them in the trunk directly over the rear axle. The extra 150lbs has done wonders for my traction. Probably doesn't help the MPG, but oh well. Neither does sitting in traffic for hours going 5mph or spinning in circles on ice. So I deal.

That in addition to the Pirelli Winters I have on the rear. Had a couple of tirespins on the way home from work yesterday simply because 5" of snow fell between lunch time and go-home time.