hmm, you have a pic of what it looks like jetman? i have a feeling that i don't have one; im thinking about the air box that is beneath the vent on the right hand side (if your sitting in the car), mine has nothing but the big air valve and the hvac raditator.
jezz prob doesn't have a/c (euro car) so he prob has one. most north american saabs have a/c, prob 90% of c900's have a/c. 87+ a/c is standard on all models(american) so none will have a polen filter. my 84' had a polen filter, they disintegrate over time, mine looked like a bunch of horse hair in a small ball, so it could be hard to spot, just make sure you remove the old plastic frame otherwise you will go nuts trying to put a new one in. rather than forking out the money for a new one, i got some sponge and put canola oil on one side, you should have seen how dirty it got after just 20,000kms!!!!!
It was interesting today driving in the rain. I was driving a Volvo V40 with aircon (new car every day of the week, that's me ) and the windscreen was steaming up. I had had the climate control set to auto at 20ºC, and when I switched to defrost setting, the aircon came on and it blew cold air over the windscreen, which cleared it in seconds. Normally in my non-aircon Saab I'd blow hot air on the windscreen.