was doing my 12 month maintenance plan & found that my X never had the in cabin micro filters installed . glad i was replacing them. after i was done & was driving around i noticed that they leave much to be wanted in terms of filtering. i was thinking & wondered what any engineering types thought about (or knowledgeable people =) adding carbon rocks (like the kind you put in fish tank filters) and then securing it down with a screen. would eliminate odors & help out if you drive by a sewer or a sulfur plant often =p.

Hey, they do a great job of restricting the air flow once they get a little dust on them

Those things are worthless, don't waist any money or time to to improve them. Unless you want to do it for the industry, for they are all the same, worthless.