I changed the cabin air filter at around 60,000 and it was loaded with crud.
If you look under the dash, to the right of the gas pedal, you'll see a little white plastic door. The filter is inside that door and it is in three pieces that interlock with each other. It is a royal PITA to change. You slide one out at a time, then you slide the new ones back in one at a time. Good luck.