If you’re referring to the viral “put a glass of salt in your car” hack, the main idea is that salt can absorb some moisture from the surrounding air.
🚗 What it can actually do
A container of dry salt may absorb a limited amount of moisture in a confined space. Some people therefore place a small open container of salt in a car overnight in an attempt to reduce condensation.
However, it’s not a powerful car dehumidifier. If your windows repeatedly fog up or the interior is damp, there is probably an underlying source of moisture.
A better way to reduce car condensation
Use the car’s A/C, even in cool weather. It removes moisture from the air.
Use the windshield defog/defrost setting when driving.
Remove wet floor mats, umbrellas, or clothing and allow them to dry.
Check for leaks around doors, windows, the windshield, and sunroof.
Replace a damp cabin air filter if your vehicle manufacturer recommends it.
⚠️ Don’t leave a glass container where it can tip over while driving. Salt water can spill and contribute to corrosion or damage electrical components.
So, the salt trick isn’t completely mysterious—but proper ventilation, A/C and fixing the source of moisture are much more effective.
