If you’re one of the millions of Americans who has more than one vehicle, or a boat or RV besides your regular commuter, there are doubtless periods of time when you won’t be using your second set of wheels (or keel). Even if you’re not living in an obviously tropical place like the Pacific Northwest of Florida, you’ll want to think about avoiding mold when you put your ride up for storage. The last thing you want to see when you take it out for the first spring spin is to see a moldy interior. We’ve come up with a few ways to help you avoid this.
Prepare By Drying and Detailing
Prior to storing your car, it’s a good idea to run the heat for a while inside. This dries out the inside of the vents. If moisture remains in the recesses of the ventilation system through a long, wet period of time, mold will grow in there. If it has grown, you’ll smell it. 
Detailing the vehicle, boat, or RV prior to storage is also a great idea. This makes sure to eliminate any places holding dirt or moisture – places that would make an ideal spawning bed for airborne fungus.
Mold grows in stagnant, humid air. Any way you can keep the air dry, moving, or both, is going to be a way to avoid mold. Some people run a fan inside the car or outside it within a garage. A good dehumidifier is the best friend of many a shop owner in a wet environment. Buying one of these is a pretty fail-safe route to mold avoidance.
Keep the Air Moving
To keep the interior dry, we’ve heard of people running a light bulb inside the vehicle. The light should be on an extension cord running to a nearby socket, it should be of an average voltage, and it should not be touching any piece of the interior. This is an original way to keep it dry in there and sounds like it would work, but we haven’t tested it. Let us know if that’s something you do. Another means to a similar end is dropping a large bag of dessicant – those dehumidifying pouches you find in bags of beef jerky, among other things, into the interior of the vehicle. This could work especially well if you know hot-spots for mold buildup within your stored vehicle.