The northwest is an exceptionally wet environment. Even though our cars have seals to keep out water and moisture, there are times that the interiors of cars get wet, and stay wet for days and weeks because of broken windows, leaky window seals, and windows left partially open. That moisture QUICKLY forms live mold on pieces like the headliner, seatbelts, seats, carpets, under seats between seats, behind door panels, etc.
The common–and wrong–response to to shampoo and scrub the mold. This seldom works, as adding more moisture to the interior of your car simply gives the mold more opportunity to grow and expand.
1. Dry out the car. Usually done using fans or the car’s heater.
2. Disassemble the car. Remove seats. Remove headliner. Remove carpet. Check for mold.
3. Remove mold with steam cleaning and treat it with mildewcide–allow to dry naturally.
4. Many, many components cannot be steamed clean. Seatbelts often are permanently stained and must be replaced. Carpets and the padding beneath often cannot be salvaged and need replacement; same for headliners.
5. Reassemble car with new and cleaned components.
Unfortunately, mold grows in places you cannot obviously see, so a thorough dismantling of your car’s interior is necessary. Yes, this is expensive and can take more than a week sometimes. But we always manage to fix the problem permanently instead of superficially putting the problem off repeatedly with “spot” cleaning.