1) Perform any maintenance that you have put off for one reason or another – Now is the time.
2) In addition if there is a want list or major project – now is the time – not when you wish to use the car.
3) Always change the oil before putting the car away; there are contaminants in the oil that should be removed or they will harm the bottom end of the engine. Always bring the engine up to operating temperature before changing oil.
4) Fuel – Now there’s a question. I recommend using a product like “Sta-Bil” added to the fuel. Some recommend keeping the tank 1/2 full and topping it off in the spring. I like to fill the tank up so there is less surface area exposed in the tank. Todays fuels that contain ethanol hold water in suspension in the fuel. Sitting in cold weather there is fuel separation which causes damage to the fuel system.
5) Over inflating the tires by 5psi to keep the tires from deflation and flat spots.
6) Polish the car and chrome to keep the cosmetics good order
7) When storing the car for the winter if it is a manual transmission, it is better to leave it in gear then to use the hand brake, as older cars have a propensity to have their hand brake seize from long periods of sitting.
8) Hook up a maintenance charger to the battery. You can leave it plugged in without worry and the battery will have a fresh charge in it when you are ready to roll out in the spring.