I was looking through the 2000 Saab 9 5 owners manual today looking for info on all the recommended maintenance intervals, and I noticed something ive never heard of before. There is Cabin air filter intervals at every 30000 miles, and right under that is "Cabin Air Absorptive Filter." Not only have i never heard of this but there is no info on google or anywhere else ive looked. It says to change it out at 60000 miles. Does anyone have a clue what this is?