I purchase a 2011 Limited 4WD Explorer in July. I was recently on vacation this past weekend and encountered a lot of rain. When my 8 year old sat in the 3rd row and buckled the seatbelt, water started streaming down the webbing and I also noticed water on the speaker grill. This has happened twice so far. This was the on the Right Rear 3rd Row. Any idea where the water is entering?