I stored my roadster every winter when I lived in Idaho. I did what Tom has suggested, wash, dry, wax and cover. I even vacuumed the car, treated the leather and cleaned the windows. I always left it with a full tank of gas (never used a stabilizer), pumped the tires up to 45 psi and rather then disconnecting the battery, I used a motorcycle slow charge, about 2amps and left it on the car. I never had a problem and before driving her again in the spring, I lowered the tire pressure and warmed her up slowly.