For those that like to let their car warm up (like myself), get a remote start. They are not that expensive anymore, and if you're even slightly mechanically inclined, you can hook it up yourself. I got one off Ebay for about $40, and I would hate to be without it. I can even leave my car running without the keys in and run into the store if I like. Here in Atlanta, it's usually to keep the air conditioning on as opposed to the heat though.