Originally Posted by LiM3y
Your best bet is to buy a set of 18" x 8" rims with 235/40 R18 winter tires on rather than try and fit a set of winter tires on the OEM rims. Tirerack supplied Sport Edition A7 are a solid rim for this purpose. This set up performs much better (better rear traction) in crap conditions that the wider tires (well it does in New England with our wet snow).
I upgraded from Bridgestone LM-25 to Nokian Hakkipillata (wrong spelling?!), and these too are significantly better winter tires than those offered by Tirerack (a New Hampshire buddy recommends these tires to his customers who absolutely need to travel in any conditions over other brands).
I agree that 18" wheels / tires is the better option. If you want to go this route I would get a set of OEM 219M 18" wheels. Buy a used set from a forum member... I am not a fan of cheap wheels.