[dwathencars]

I needed to store one of our collector cars in an unheated garage for two years when I was working outside the US for a while. I used this storage bag that you pull the car into (a little cumbersome to do), put some big bags of desiccant in the car, extract all the air from the bag with a vacuum cleaner, then seal the bag with this huge twisty clamp. It worked remarkable well. I recall the kit costing maybe $200, and it's reusable.

I think the damage to a car in a unheated garage occurs when the temperature passes thru the dew point, and condensation forms inside cavities and on unprotected surfaces. That, and varmints. We've all seen nests and cobwebs....