One of the most essential tools for replacing an air filter is not a screwdriver or 10mm socket, it is a vacuum cleaner. Outside of the air filter housing, dirt and leaves can accumulate. These need to be removed before the cover to the air filter is removed for inspection.
Inside the air filter housing, larger pieces of leaves and even rocks could be at the bottom. You may even see accumulations of sand. When the old filter is removed, debris trapped in the pleats can fall into the housing
Rodents love to store food in the housing and even make it into a home. Chipmunks like to store nuts, while mice prefer pet food. As for bedding materials, mice and chipmunks love to destroy hood liners for a soft, comfortable bed like on this Toyota.
If there is pet food, advise them that they may need a new method to store cat or dog food in the garage. Using a vacuum to remove this stuff housing will give a new filter a longer life.
As for keeping the rodents from nesting, the jury is still out on this one. Some remedies include Irish Spring soap, dryer sheets and pine-scented air fresheners stashed under the hood. Some online gurus even advise spraying the tires with deer scent. You can leave this part up to the customer.
This video is sponsored by FRAM