My Trunk has been full of water after heavy rain. I stripped out the cladding and located where the water is leaking from. I've sealed all around the lights but it's unlikely the water is coming through there, it's more likely to be flowing down the side of the rear windscreen under the black plastic piece on the side of the lights and through the gaping holes there. I'm being told that I can't completely seal that area as that is where the air escapes from closing the boot, the question is if I can fill the top part so that the rain will just flow over it and away from the gaping holes behind