try lowering the hatch lock. take off the rear cener panl trim (inside the car, not the actuall outside panel) and loosen the three bolts and push it down some. itll make the hatch close tighter and prevent future squeeking too. i did it and now my hatch doesnt get wet anymore (never did it as much as you say yours did, but in a real heavy downpour, or if put a constant stream of water to it, it would get a little wet inside. not anymore)
