I always use a fuel stabilzer for winter storage. Canadian Tire has a couple of brands. I consider it cheap insurance up here in the Used To Be Great White North.
Not too sure about carpet under the tires and flat spotting. If that's a concern lift the car on axle stands. I have maxed the air pressure to avoid flat spotting.
Cracking open the window allows the interior to match the humidity of the dryer winter air. At least that's what I always thought.
Last edited by jafxdwg; 09-26-2012 at 07:58 AM.
Reason: additional info