I found a clue. The rubber seal is retained on the door frame flange by a steel inset compression "spring". I found rusty stain transfer onto the aluminum flange, indicating water getting into the u channel of the seal. From there, it could theoretically run along the seal channel and down to the bottom corners of the seal and exit to the floor. I am looking for alternatives to the OE seal and remove it entirely.
"If the women don't find you handsome, they should at least find you handy." - Red Green