AC or Cabin Filter Replacement

AC or Cabin Filter is the filter for your AC system.  The air outside the car enters the AC system through this filter.  So obviously from a health point of view , it makes sense to make sure it is replaced periodically.  For normal usage i would recommend changing it  once every 6 months.  See examples of Cabin filters below :

Wally and parts store does stock filter for most popular cars. For European cars you might want to get this online or from the Parts section of the Dealership.

In some cars this filter is in the front of the hood , directly below the region where the Wiper arms are resting.  You may need your small socket and extension to remove the cover of the air intake box to reach that filter. See the picture below for an example of a BMW cabin filter in the hood area.

For other cars this might be behind the glove compartment area.  To replace the filter,sometimes you have to  empty and remove the entire glove compartment. You can do this by prying gently on the hinge supporting the glove compartment door. Once the glove compartment is off , you can see a "black" air intake box fixture , pop its cover open you will have access to the AC filter. In some instances the AC filter can be accessed without removing the the entire glove compartment. A cover for a the filter area will be visible in the back as soon as you open the glove box.

Note the arrow mark on the filter (showing direction of air flow) before you remove it.  Replace with the similar kind and note the DIRECTION of air flow and match it