[Skyhammer]

I live in rather dirty environment, we have 35 miles of dirt roads on the ranch.
50% of my total miles are on dirt roads. I have 10k on the Tundra and over 3k miles are in 4WD, so most folks probably won't get their filters that dirty. When I get a new filter I will take apart the old one and take pictures of the black pleats.
The reason I looked was because the leaves were rattling around. On the Titan, the output from my vents dropped by 50% or more because of the clogged filters. The drop in output was gradual, so I didn't really notice until it got hot out and I could not get the cabin cool.