Decided to change out the cabin air filter on the Matrix - since the windows were starting to fog up easily and the HVAC system seemed to have some issues with performance.
Also included some pics - as people like to see photos. Replaced with a Home-made deal from one of those washable foam filters for your furnace/central air home systems. Also to iterate to the DIY or ones thinking about this job - it really is a 5-10 minute job. No sense paying someone else to do it - unless you don't have the time or desire to do the job. This also should be very similar to the 9th gen Corollas - but in case it is not, please let me know.
Easy as opening the glovebox and locating the screw on the side.
Remove the strut off the stud - Press in the sides of the glove box enough to clear the limiting tabs
Voila - you can see the blower unit and the cover plate for te cabin air filter - just squeeze in the tabs
Close up the cover plate and the screw for the strut rod - make sure you don't lose them
Peek at the wickly nasky air filter that is in there
Close up of the filter - also dimension for those that want to make you own (assuming that the Corolla is the same size)