So I did the job and highly recommend no more than a two year change interval (keep in mind tons of trees around our house).

The filters were cruddy but not solid black. More like gray with lots of broken up tree leaves, needles, etc. stuck in the grooves.

The job IS a pain, but having the necessary bits apart is a good chance to clean up the whole area.

Hope all this information helps someone. Best regards,

__________________
Michael

1988 300 SL (5 Speed)
1994 E320 Wagon
1997 C230