water comin in through heater ducts

I have water coming in through drivers side heater duct.....the water is ruining my floor board.......So i taped off the air inlet grill in front of the windshield.....this helped a lot but it did not fix the problem.....where else can the water get in at?


Anyone have picture on how to fix this .....i know i will have to cut into the car to get to the metal under the air inlet grill......i have a feeling this will be a tough repair