how bad is winter for an old car?

make one of these to put in there, it will help keep it dry so it doesn't mold. Basically, it's a cheap light socket and bulb on an x made out of 2x4s screwed inside a metal lacquer thinner can... a home-made chicken-coop heater. I put a 100-300watt bulb in it.

that thing is wicked! i need one of those for the garage this winter!8)