Are these things a waste of money? If not where can I get one cheap. I looked around and couldn't find anything from advance or autozone. Anyway, suggestions would be appreciated.

Mike

In Cabin Filters are located behind the glove box and could be brought at your local dealer. Also recommended they install it. GL :)

Personally I find the in cabin microfilter a very important need in my 1999 Ifinity Qx4 its located behind the glove compartment and Will Be Very Costly At The Dealer To Buy Or Replace.
Do It Yourself, Its Easy.
You can go to
http://www.buyautoparts.com/
and do a search it comes with all the instructions to replace it easy.

The replacement is VERY EASY. Save your money. Micro filters are a great invention for dealer gouging! Amazing we've survived for decades without them. In anycase, if you feel inclined to replace it, break out your phillips head screw driver and set aside 5-7 minutes to unscrew the glove box on either your Maxima or Pathfinder (I replaced both in about 15 minutes). THEN disconnect the glovebox light and pop the airbag connection off the back of the glove box and you will see a vertical slot where the respective filters slide in. Pop the small retaining clip off the bottom and slide it out. Slide the new one in. It takes a little fiddling to get the two piece one in (pathfinder) or the single piece one (maxima), but then your done. Reverse the process and you now just saved yourself how ever much the dealer was going to rape you for to do it. The funny part is after I replaced the one on my 2002 Maxima, I read the placard on the inside of the glove box which said to WASH it every 12,000 Km.! It also gave instructions as to how to wash it. The Maxima kit included a new placard (sticker) that sternly stated the filter MUST be replaced every 30,000 Km. No mention of washing anymore. Strange. Being to lazy to return the $54.00 filter to the dealer I put the Maxima one in. The one in the Pathfinder looked pretty much brand-new after 3 years and only 26000 miles so I left it in.

By all means install it your self, After you remove it , you tell me if it's worth changing .

If you haven't replaced it yet, here's a site with for buying and replacing.

http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=999M1-D4005