Ya might want to change your "Cabin Air Filter"
Instructions shown here compliments of "Andrew" from another thread.

Once you remove the lower cover/panel under the glove box & passenger foot well area.

this is what you see...
coverattached.jpg

you need to slide back each clip (off white color) to remove filter cover... then pull filter out (it stands up on end).

pic of cover removed:
cover.jpg

pics of filter at 25k (new - old): revised m/b part number
filter.jpg