I'm also a huge proponent of the electric defog kits. We have one and it's amazing. That plus a functioning HVAC blower means zero fogging ever.
Some cars can get away with just chemical treatments on the glass, or chemical plus blower, but the Saab cannot, it fogs like mad with just those. Comes down to a combination of factors like how much natural air movement you get from your open windows, how much water your car holds onto inside, how much you're heating the floor with exhaust (which tries to evaporate the water, which then condenses on glass), and some other factors. Some cars have little to no fogging issues, some are trying to kill you through blindness. Electric defog works on just about all cars though. I love it.
Ours is the same as the bimmer world link, but we got it somewhere else.
20+ Time Loser
FutilityMotorsport Abandoned E36 Build2008 Saab 9-5Aero WagonRetired -
1989 Dodge Daytona Shelby 2011-2015 "Lifetime Award for Lack of Achievement" IOE, 3X I got screwed, Organizer's Choice