2001 Porsche 911

Interior problem
2001 Porsche 911 Carrera 6 cyl Two Wheel Drive Manual 25000 miles

I had the car service with an all points inspection back in June. I do not think they replaced the plugs, but changed the oil and air filter. However, they wanted me to change the cabin air filter, but I did not do it. The car does not smell or anything, but sometimes when I am on the highway, the car gets hot inside (even though I have to shut the fan off everytime I start it). I cannot find or have any idea of how to change the cabin filter myself since it can't be a big deal although I can't find it in my Nissan Murano either. Can you give me an idea of how to get to it?
October 15, 2008.

Porsche- It is located under the hood, passenger side in front of the heat/ac plenum. See pic

Nissan- Remove glove box, see pic 1 , then the cover and filter should eb visible see pic2

Oct 15, 2008.