[patrickt]

Many people do not know thier Camaro has one. The passenger compartment air filter removes most of the pollen and dust from the air that enters the vehicle. The filter will need to be replaced periodically. Should be replaced every 12 months or Maint II service. Using the climate control system without an air filter installed is not recommended. Water or other debris could enter the system and result in leaks or noises. Always install a new filter when removing the old filter.

Here is how you change it out

Remove the passenger side wiper cowl (held in place by a few push retainers Item 1 retainers item 2)
Remove the passenger compartment filter door. (Thin door see picture below item 10)
Pull out the filter and install a new one (item 9)

All this takes about 5 minutes and will make the air coming through the vents a lot easier to breathe especially during allergy season.