Boy - did this tread go off the rails. The OP wants suggestions on how to hanlde his RWD in the winter/snow. An extra set of winter tires/wheels is a given. I just bought Michelin AP3s; we have had 3-6 inches over the last 24 hours in Chicago and I have had no problem. This includes driving through snow packed ally ways where there has been no plowing. Will it ever be as good as AWD with the same tires? Of course not. However, compared to the stock tires that come with the car, it is MUCH better. For added precaution, put some extra weight in the trunk.
SCCA & Midwestern Council W2W, '91 Spec Miata, '07
NASA TTD Champion, Midwest, '99 M3, '09
Midwstrn Council TT Champion, BS, '10 GTI, '10 &'11