Any ideas on how to get rid of foul smelling air when using the vent setting in my 97 taurus? Smells like I'm drawing in air from a garbage dump, but when using AC, I don't notice anything nasty smelling. On pure vent, it stinks. I've changed the cabin air filter (and change it every year like clockwork), but that didn't alter anything.
Are there any sprays etc that I can use in the vent outlets, or should I be doing something more drastic?