I don't know why Mazda decided to put the cabin air filter where they did in the Mazda 3. Not only is it a pain the *** to get to the access door but also trying to get both filters on top of each other once inside the housing. I don't know about the newer Mazda 6 but a friend of mine has an 04 6 and his cabin air filter is behind the glove box and is easily changed. (I just felt like complaining)

 

what year is yours because my 2006 3 also has the cabin air filter behind the glove box

 

I have an 06 3 touring. My access port for the cabin air filter is on the passenger side near the heater core, just below the glove box to the left. I thought only the Mazda 6 was behind the glove box. Is your cabin air filter a two piece filter?

 

nope its one