here are the schematics for the door:
[
www.autoatlanta.com]
[
www.autoatlanta.com]
I have it in my head that there is a plasticized foam sheet (as opposed to plastic like in GM) between the door and the door card to force water to the bottom, depicted in the second link as #4. Wet door cards are often caused by a defect in that liner.
But as you note, it could also be a plugged drain. If that were the case, I would expect to hear water sloshing when you opened and closed it.
either way, I would be removing the door card to see what gives. You can see there are a number of gaskets. It is certainly possible one or more are defective. But i would start with the main sheet thing.