The mildew smell in a car is normally caused by moisture. You could have spilt some liquid, your sunroof drains could be leaking or there might be moisture inside your air conditioner unit.
The easiest way to solve get rid of the mildew smell is to let the air circulate throughout the car to help get rid of bad smells.
- Remove the cause of the odor by vacuuming the car seat.
- Scrub the seat with an OxiClean Baby solution or a similar product, which will clean tough stains without leaving marks. Allow the seat to air dry.
- Let car seat air dry.
- Allow car seat to air dry once again.
Mildew Removal Tips
You could also spray the seat with 75 % rubbing alcohol and 25 % water to remove the smell and kill the mold.
Do not use bleach on a car seat, it will leave white spots.