Right side of the car. The lower left quadrant of the picture is the triangular water collector bin above the hinges of the right front door. The small pipe in the middle is the water drain of that bin. The bottom right of the picture shows how that pipe enters the engine bay (in the corner above/behind the master brake cylinder). A rubber hose will be attached to that pipe in the engine bay, to guide the water downward to a hole in the bottom of the car.