Cabin Filter Info 

Also called pollen filters, these help clean the air that is being sucked into your car’s HVAC (heating, venting, and air conditioning) system. By cleaning the air that’s being brought in, they help ensure your HVAC system doesn’t get clogged up and that you get fresh air coming out of the vents into the cabin.

If you look at a brand new cabin filter after a week of use, you probably won't see any difference. After a year? It'll look more like this:

Cabin Filters new vs old.jpg

Yes, that’s really what air filters can look like at the end of their service life. The leaves, bugs, pine needles, and other crap in there would have gone into the HVAC system and either clogged it up or been blown into the cabin of your car.

Aston Martin recommends cabin filters be changed every 20,000 miles or 2 years (whichever comes first), and doing so helps ensure you keep getting fresh air blowing through the vents. If you have allergy problems or live in a harsh climate, it may be better to change them as frequently as your engine oil (10k miles/1 yr). They're easy to replace and inexpensive to buy, so it won't be much of a burden to do it more often than every-other year.