My air filter is close to coming due to be replaced, I just pulled the old one out, but for the life of me cannot find anywhere to buy a new one! I went to my nearest Caterpillar dealer, they said it was a Fleetwood part. So I called the fleetwood parts department in Greenville, SC, they said it was not a fleetwood part, and to get one from NAPA or a local Auto Parts store. This thing is sitting in my bedroom floor and is at least 2-1/2 feet tall and about a foot in diameter. Has anyone ever changed their air filter? Where do you get one? Thanks.