Make sure the car cover is designed for year round use for one and your also going to want to get a Battery Manager from Griots Garage. You can actually get both items from Griots and remember, you get what you pay for from them. I have the Battery Manager and its great as its got a computer chip inside of it that doesn't allow the battery to be overcharged like most trickle chargers do. A couple other things your going to want to do is:

- fill the car up so its full of gas.

- air up the tires a bit more as your going to lose air for every 10 degree drop in the temp.

- wouldn't hurt to place a brand new box of Arm & Hammer baking soda opened up somewhere in the car to keep down moisture.

- make sure the oil isn't real old either as you get condensation build up after it sits for sometime.