Prelude SIR-T

What is the recommendation on these. How often do you need to replace it and where is it located?

BLKFLSH

The recommendation in the owner's manuals is for 30k miles, but it says to change it more often if you drive in dusty conditions. It's very easy to remove and check it out for yourself, so I check it before the mileage comes up. I've changed my cabin filter twice in 52k miles. Here's a link on how to change it (no tools needed). Your owner's manual should also have the directions.
http://www.micronair.us/assets/pdfs/85.pdf

union122

Can someone help me locate the cabin filter for a 98 -ex?thanks,