While I had my dash torn apart to install a uPAC iPod and Aux Input adapter I figured that I would also perform a mod I have seen mentioned elsewhere, adding a Cabin Air Filter. In GM's wisdom they use a lot of the same parts across several marques and models, and the CAF-equippable air box is one of them. If you looked behind your glove compartment you would see this taunting you :
But what exactly do you need to do before and after cutting on the dashed line?
Required tools & equipment:
A really sharp knife or a Dremel tool with a saw attachment
A 10X20 or 10X30X1 air conditioning filter
A sharp pair of heavy-duty scissors
Duct, Gaffer's, or aluminum tape
Glue or other adhesive
Carbon-impregnated pre-filter, cut to size.
Velcro to secure pre-filter to main filter
How to do it:
1. Open the glove compartment and remove the contents. Squeeze the sides of the glove compartment inward so that you can clear the stops and lower the door.
2. Look carefully at the HVAC air box that is behind the glove compartment door. You will see an area surrounded by a dashed line that contains the message CUT ON DASHED LINE TO ADD FILTER. Using your knife (be careful, the plastic is thick and firm) or Dremel tool, cut along the dashed line. Note: in the picture below, the yellow circles and ovals highlight where the removable filter door attaches on the cars that are so equipped. I don't know the part number, but you might be able to find it checking the Saab 9-3 parts manual as it supposedly has a CAF.
3. Remove the cut piece. I used mine as a gauge to measure how deep the cutout is. It turned out to be 8 inches - but not according to this ruler:
4. Measure and cut your air filter to size. I recommend cutting it between 1/8 and 1/4 inch short.
UPDATE: Someone on the G6P forums did this mod and posted that the Fram CF10361 fits fine. Better than the hack job I did below!
5. Optional but recommended step: Cut a piece of heavy paper (I used the insert from the filter package), cardboard, or similar to form a complete frame for the filter. Another thing you could do is cut the filter about 9 inches long, cut the cardboard frame back to 8 inches, then shove the whole thing in to get a seal.
5a and 5b. I added a carbon-impregnated pre-filter to reduce noxious odors coming in from outside. To do this I added glued-on velcro tabs to which the media can grab. See the post below for images.
My final filter size including the pre-filter is 10 inches wide (the cutout width) by 8 inches (the depth) by 1 inch (most A/C filters are actually about 3/4" thick).
6. Install the filter into the air box. Note the air flow direction arrow on the filter should be pointing DOWN as the outside air comes in from the top of the box as it is drawn by the fan.
7. Seal the air box with your choice of tape. I used Gaffer's tape since it will leave far less residue than duct or aluminum tape, and also will be easier to remove when it's time to change the filter.
8. Wrap the remaining filter up in plastic and save it for the future.
9. Enjoy your clean air!