AUTO DRY Car Moisture Absorber. Sometimes we don't even realize how much moisture accumulates inside our cars. High humidity levels are most common during the fall and winter months, when temperatures drop. They manifest themselves through fogging windows, unpleasant odors, and accelerated microbial growth, which also exacerbates corrosion. There are several ways to deal with interior moisture. It's worth starting by thoroughly vacuuming the entire car and unclogging the drains under the windshield. If that doesn't help, check the condition of the cabin air filter. Remember that simply turning on the air conditioning and setting the temperature to high can have a beneficial effect on fogging windows: if the system is working properly, it will instantly dry the damp interior. Another way to combat moisture in your car is to use an inexpensive car moisture absorber. It's essentially a small bag filled with water-absorbing grains, which you place inside the car and wait until it fills with water.