We have the same problem. Water enters the inside of the door through the seal at the base of the window (this seal is not intended to be water tight) and water is intended to flow down the inside of the door to the bottom of the door where it exits through designed drain holes. However, if the...
We just had this problem and the cause was the transmission mount. See attached photos. Big concern is why this would fail after only 20,000 miles and 2.5years.