I don't recall previously having the air filter changed, but the filter I removed looks rather clean for 26,000 miles. [Broken External Image]:http://www.mikepaul.com/OEMAirFilter.jpg The notches on the sides allow the filter to fit properly, but the NAPA 2306 I managed to track down doesn't have them. I had to cut the extra material off with snips the NAPA store had on the shelf. I wrote Wix, the listed manufacturer, to see if they knew it wasn't correct. Maybe new ones are OK and I got an old one. If anyone has used a Purolator or Fram filter and knows if they are OK, please let me know...