I had a leak last year similar to XCross69. When I parked slightly uphill, I got a soggy passenger side. I found it was coming through one of the screws that hold the cowling under the windshield wipers. When parked uphill it made the dripping water fall straight down through a cold air intake hole that's in the trough at the bottom of the windshield. The drip fell down the hole, which is behind the glove box, to the heater fan, then to the floor. Parked facing downhill the dripping water would usually be caught by the trough. I fixed it by putting a drop of silicon in the empty screw hole & putting the screw in. Then from the inside, I sprayed Spray-on rubber/sound proofing stuff up behind the glove box, through the cold air intake hole, to the underside of the screw. It was a bit of trouble & frustrating, but at least it wasn't a cracked weld like I've read about. Hope that helps (if it makes any sense).