Do you think you have an in-cabin air filter in your Nissan? I did. I bought a new '02 PF a couple of years ago. The in-cabin air filter is shown on the factory sticker under "Options Included by Manufacturer". It says "In-Cabin Microfilter $59.00". I also found stickers in the glove compartment that explained that the filter had to be changed every 6 months and that the first filter was installed when the vehicle had 5 miles on it.
Today, I had some service done on the car at the dealer. While I was there, I went to the parts dept. and bought a new cabin air filter element. I figured that I should change it after two years. I took the glove compartment out and found that no filter had ever been installed. I followed the directions with the new filter and cut the box to install the filter.
I plan to take this up with Nissan next week because I don't think I should pay for a filter that I never got. Has anyone else had a similar experience?