Where does all the water come from?

I've also have had some water in my air duct, came in from the cowl?.

Rubber mats are a culprit for trapping in moisture also.

yeah you know in the cowl there is a little stove pipe that lets air from outside channel in the car via. the little doors you can open by the heater box and a driverside vent box. my water only comes in at wash time....