The first thing that comes to mind is a plugged vent. On the air intake vents below the windshield is a vent that takes in fresh air for the cabin. It also takes in water and snow. If the drain gets plugged you can have an overflow in to the cabin of the car.
Second suggestion if the first does not cure the problem is to think about a leak at a window. I have seen a window and in the case I am referring to, the windshield, start to rust the metal where the window contacts the frame of the car. Once that was located the rust could be neutralized and the windshield resealed.
Tuesday, December 16th, 2008 AT 7:52 AM