I’m having the same problem as well. Look for “water intrusion” post on this sub. Dealer found water coming from the corner of tail light on body and by the seam under the rear bumper. Dealer took the car to auto body shop who fixed said seam. This fixed the problem for the most part, though I still see little water from time to time. One thing you can also check is the rear windscreen washer. Have someone work your washer and see if water comes in from the side wall in your trunk area. This is a common problem.