Almost half of the vehicles that come equipped with a cabin air filter have the filter positioned inside of the glove compartment on the passenger side of the vehicle under the dashboard. After simply opening the glove box door, removing or “dropping” the door will expose the location of the Cabin filter. There should be a “plate” that should be gently pushed and pulled out to reveal the cabin air filter. Some vehicles come equipped with a specific housing in which the cabin air filter sits into, some vehicles do not have this housing. Gently remove the cabin air filter and ensure the new cabin air filter is the correct filter (ensuring the filter is the correct side up to the air flow) and place back into the housing. For cabin air filters that are located under the hood or under the dashboard, this may require a more specialized installation. Always refer to the vehicle owner’s manual for all installations and locations of cabin air filters.
Hold the existing filter up to a light and attempt to see through the media. If you cannot see through it, it may need replacing. If you don't remember ever changing your cabin air filter, it may be time to replace it.
Over 155 million cars on the road need cabin air filters replaced, however most consumers are not aware they even have one. Cabin air filters should be inspected at least once-a-year, however Bosch recommends following the manufacturer manual for procedures for servicing a vehicle.