Weather you are putting the vehicle away until next weekend, or putting it into hibernation for the winter, here are some of the most important things to consider, references, and my some of personal routine for my show car.
Car cover
I typically preach against using a car cover, if the vehicle is being stored on your property, somewhere that the vehicle is easily accessible to you. A car cover isn't worth the risk of damage like micro marring. However, if you won't be able to access the vehicle as easily, then a cover may be worth using.
Clean the vehicle
Wash the vehicle before you put it in storage, this will minimize the possibility of causing grime related defects in the paint and interior down the road.
Tires
If a vehicle is left stationary for too long, the tires could develop flat spots from the weight of the vehicle pressing down on the tires’ treads. This occurs at a faster rate in colder temperatures, especially with high-performance or low-profile tires, and in severe cases a flat spot becomes a permanent part of the tire, causing a need for replacement. If your car will be in storage for more than 30 days, consider taking off the wheels and placing the car on jack stands at all four corners. With that said, some argue that this procedure isn’t good for the suspension, and there’s always this consideration: If there’s a fire, you have no way to save your car.
If you don’t want to go through the hassle of jack stands, overinflate your tires slightly (2–5 pounds) to account for any air loss while it hibernates, and make sure the tires are on plywood, not in direct contact with the floor.
Battery
An unattended battery will slowly lose its charge and eventually go bad, resulting in having to purchase a new battery in the spring. The easiest, low-tech solution is to disconnect the battery cables—the negative (ground) first, then the positive. You’ll likely lose any stereo presets, time, and other settings. If you want to keep those settings and ensure that your battery starts the moment you return, purchase a trickle charger. This device hooks up to your car battery on one end, then plugs into a wall outlet on the other and delivers just enough electrical power to keep the battery topped up. If you use a trickle charger, make sure to place a clean towel in between the umbilical cord and the paint, to minimize the risk of damaging the paint.
If you want to remove the battery but still have it on a battery tender, set it on a piece of wood in your garage and attach it to the tender. Make sure not to lose track of the two battery bolts. Keeping your car’s battery charged prolongs the life of the battery, and you don’t have to wonder whether your car will start.
Warning: Do not use a trickle charger if you’re storing your car off property. In rare cases they’ve been known to spark a fire.
Run the engine
My personal rule of thumb is to start the engine once a week, and allow the vehicle to get to full operating temperature. However, you can go as far as a month between starts before you risk causing un-necessary damage.
Fuel
Before any extended storage period, remember to fill the gas tank to prevent moisture from accumulating inside the fuel tank and to keep the seals from drying out. You should also pour in fuel stabilizer to prevent buildup and protect the engine from gum, varnish and rust. This is especially critical in modern gasoline blended with ethanol, which gums up more easily. The fuel stabilizer will prevent the gas from deteriorating for up to 12 months.
Check your coolant
If you don't store your car in a climate-controlled garage, be mindful of how much coolant-to-water mixture is currently in your car. Without the right amount, the water can freeze and expand, causing catastrophic damage to your engine.
Parking brake
For general driving use it is a good idea to use the parking brake, but don’t do it when you leave a car in storage long term; if the brake pads make contact with the rotors for an extended period of time, they could fuse together. Instead of risking your emergency brake, purchase a tire chock or two to prevent the car from moving. If the vehicle is manual, leaving it in gear would be a great secondary safety.
Plug the exhaust
Small, cozy places like exhausts and intake boxes are prime real estate for rodents and other sorts of small creatures to thrive during the winter. Save yourself the headache and make sure there's nowhere for the little critters to enter your car.
Insurance
You might be tempted to cancel your auto insurance when your vehicle is in storage. Although that might initially save money, there is a chance that the insurance company will raise your rates due to the gap in coverage, which could cost you more in the long run. This can vary based on where you live and who your provider is, so contact your insurance company to see what options are available to you.