I had the afterblow kit installed in my 98 mystique this summer under warranty. It seemed to solve the problem for a while, but now a few months later I can smell the familiar musty smell again. It does indeed remove some moisture from the ac/vents, since I can see the moisture accumulating on the inside of my windshield when I've come out to the car soon after the blower runs.
I'm taking my car back into Ford to have it deodorized again since the musty odour causes my nose and throat to constrict.