My Jeep Wrangler Rubicon uses 2 of these filters behind the glove box. They are fairly easy to install, and they do work based on seeing how dirty the old ones were. I installed the original ones several years ago, as they are not installed at the factory for some reason. There are 2 spaces in the ventilation opening after removing the glove box unit - it just comes out after pushing in the plastic sides and pulling back. Well worth the money, especially if someone in your family has allergies, etc.
There are great to add to the Wrangler, most don't know about them, or remember to check. Just wish the "air flow" direction was more obvious. I think its downward.