This 2005 Mazda MPV came in with the complaint that the air flow from the vents was very weak although the fan motor seemed to be blowing fast. Sounds like a restricted cabin air filter to me. The cabin air filter on this vehicle is located behind the glove box.
To change the filter start by opening the glove box. By the way having this much stuff in you glove box is not a good idea. Especially if you tend to put loose papers or napkins in there. It is very common to have these items get sucked into the blower motor impeller or blade.
Once the glove box door is open the sides have to be pushed in order to allow the stop pins to be released.
With both stop pins released open the glove box fully.
On the left side of the glove box there is a hook and pin that separate. The glove box has a slot that hooks over the hinge pin. The glove box must be fully opened as described earlier. If you are sitting in the passenger seat, pull the left side of the glove box towards you so that the hook, on the lower left corner of the glove box, will come off of the hinge pin. Make sure that your pulling angle matches that of the slot/hook.
With the left side released the right side pin can be slid out of the hinge socket.
Now that the glove box is out of the way the cover for the cabin air filter can be removed. Depress the retainer at the left side of the cover as shown below.
With the cover pulled off you can now see the actual filters.
Slide the left filter out first. Then the one one the right can be removed. Put it all back together and you are done.
These are the old filters. It is a little hard to see but the filters are full of a very fine dust. This vehicle obviously travels down a dirt road on a regular basis. At least that dust is not stuck in the evaporator core or the passengers lungs.