Get. Winter. Tires. I don't know how many times I have to say it before it becomes common sense. Do not drive your vehicle on summer tires in the snow. Summer tires are too far below their operating temperature in freezing weather, and their tread design is inappropriate for traction. Get a good set of Blizzaks or Pirelli Snowsports for your vehicle on an extra set of wheels and just switch back and forth as weather permits. You will save yourself lots of worry, and will have the best of both worlds. Combining a proper winter tire with the excellent traction and ESP system our cars are equipped with does wonders. I have yet to have any scary moments in my car, and we've been sitting on a foot of snow for the last couple of weeks.