I just changed the filter on my 2001 Acura due to the process I could tell this had never been done before. The car has 148K miles on it. When I removed it I found no leaves or dirt in the box. I changed the filter on my 2010 Mazda Speed3 with 105K miles last month, when I removed it I found leaves, pine needles, & tons of dirt. I have only put 3K miles on this car since I picked it up used so I cant be sure if it was the original filter or not. Below are pictures of both Acura is the one with new and old in the picture: