Also check the foam drain tubes at the bottom of the heater box. These disintegrate, and then the water travels under the carpet from front to rear. Pull the vertical carpet panels along the transmission tunnel to check the tubes. For the hose test, run water around the base of the windshield wiper, it drains into the heater box and out through the foam tubes (should normally drain out under the car, on top of the transmission). Water leaks can be a PITA to track down...
