For you guys that will like to have only filtered air coming inside the car, here is a simple,CHEAP and efficient way to do it as I did on my 2000 GTS. I bought from OSH,you can find it at Home Depot or similar places, a "two phase electrostatic filter" which is a fancy name for a dual density/material foam filter that is used in furnace or A/C for a house. The brand name is "The WEB" ans it is claimed to remove over 90% of dust and pollen, down to a size of .245 to 80 microns. What you need to do is to cut a 6 inch diameter piece and put on top of the heater/A/C opening and under the round rubber gasket. No need for glue or anyting,when you close the hood, the gasket compress and "sandwich" the filter between the gasket and the plastic frame of the A/C/heater opening. Also since the rubber gasket insulate it from the engine heat and only fresh outside air go through,there should be no problem of melting it. Luc.