Cmax air filters are tedious. My engine air filter didn't look too different to the 'mouse nest' one above. I was tempted to 'let it go' for another year, but decided to change it; I similarly sucked up some monster cotton/felt/debris. Not concerning since the filter caught it, but that was unexpected. For my cabin air filter, I threw the retaining screw away since the plastic cover snaps into place although the cabin air filter requires some gymnastics.
Greg