Have you actually seen water come from that tube to be sure that is the source? The 04 GP's have a tsb to fix the water deflector at the base of the windshield by replacing it with a tray to eliminate this problem. This is the most common cause of water on the passenger floor and is so common they had to redesign the water deflector to fix it. If you have not actually seen water coming in, I would start there. Have somebody soak the roof and windshield with a hose while you sit in the car and look for where the water comes in. Good luck.
