A car that isn't in active use still requires regular care to keep it in good condition. Protecting your car from weather damage and pests from the start, as well as properly preparing it for storage and thoroughly inspecting replaceable parts, will make it easier for your car to quickly return to regular use when it's ready.
Clean, Protect, and Move Tires
Tires are especially susceptible to damage from being out in the sun and sitting in one position for too long. If you're able, drive your car every few weeks even if it's just a very short trip to move the tires. If it's being stored long-term, the car can be mounted on jacks to take weight off the tires and prevent flat spots. Rinsing your tires every so often will help keep them clear of salt, which can cause corrosion, and buildups of dirt and debris.
Fill or Empty Gas Tank
If your car is going to be out of use for only a few months or so, fill the gas tank completely. This helps prevent condensation from building up on the inside of the tank. If it will be longer than twelve months, empty the tank completely, as any fuel sitting for that long will likely go bad and need to be drained anyway.
Check Belts and Hoses Before Driving
Belts and hoses, especially those sitting in heat or sunlight for long periods of time, can wear loose, dry out, and start to crack. While these won't harm your car while it's not in use, trying to operate the car when these components are failing could quickly cause trouble. If your car hasn't been used in a while and might be soon, give these parts a thorough inspection to check for signs of wear and tear before you start driving.
Avoid Direct Sunlight
Direct sunlight causes paint to peel, protective coatings to fade away and crack, and also dries out tires, which can noticeably shorten their lifespans. Direct sunlight is more of a problem than heat, so you can protect many of your car's important parts by covering it up partially or even completely. Unless you have a garage to park it in, car covers are preferable to shade, as leaving your car uncovered even in shade still exposes it more to the elements. If you can only cover your car partially, your tires are the most important parts to keep covered as much as possible.
Keep Pests Away
Pests nibble on wires, make nests under the hood, and drag in outside debris. You can use a mix of traps and deterrents, like peppermint oil, mothballs, and sawdust to both keep most pests away and catch the ones that come through anyway. Check your car and traps every so often to make sure they're working, and to see what you might need to adjust if they are not.
Contact an auto service for more information regarding preventative vehicle maintenance.