Passenger cab filter

Maintenance schedule for my 2003 Regal requires changing of the passenger cab filter every 15000 miles. I have a two part question:
(i) Local repair shop mechanics recommend that it should only be changed after 30000 miles. Which is the proper recommendation?
(ii) Where is this filter located? Can I change it myself?

It's all dependant on how often you use the AC or vent.

To change:

open hood
remove cowl cover, this gives you access to the filter
swap the filters, replaces cowl cover, and your good!

Thanks for the prompt response. Removed the cowl. Could not find any filter housing there. Found some padding on the firewall behind the felt covering. If that is the cab air filter, it appears to be too small than the one they selling as a replacement. Will appreciate any further directions.

Here's some instructions with links to pictures from another site. (would naming that site be considered advertising if it's another forum?)

A few weeks back I replaced the cabin air filter with a new one. Prior to this, I had a major problem with water on the floor of my passenger side, which meant that my rubber strip had fallen off. Sure enough, when I opened up the cover the little piece of rubber was just sitting on top of the old filter. (Here's a reenactment picture.) http://www.picdump.org/albums/album479/100_0044small.jpg

So I popped the rubber strip back onto the metal lip
http://www.picdump.org/albums/album479/100_0045small.jpg
and dropped in the new filter.

The filter I used this time around was made by ATP and was part # GA-1. The cost for this filter was $24.81 at the local parts store. After installing this filter in my car, I decided to pick up a Delco one for my mom's car. The Delco part number is 10446783 and the filter ran me $21.22 at the dealer.

As onecan see in this picture
http://www.picdump.org/albums/album479/100_0043small.jpg
the old Delco filter has many more pleats vs. the new ATP filter. While I can see a slight advantage of more airflow for the ATP filter, it is not apparent at all through the vents. The Delco definitely holds the advantage for dirty/dusty conditions. Next time I'm going with the Delco filter for sure.

lawless, on the subject of advertising, if another forum or website has a useful, relevent piece of information to add to the thread, then by all means, post it, but if you're sole intention to post is the following, then don't:

Hey Guys, come to newforumthatsreallygreat.com !!!! We need new members, and we say we have good info but we really dont!!!!

ok thanks tman2093 if it's relevant in the future I'll post and add a link.