Yeah, it is definitely concerning. my truck had water retained on the running board of the rear drivers side door too, but more water on the front door. So much that is pools out from the door when I open it. I am worried about corrosion in the long run as well as additional moisture getting into the electronics and carpet. I live in CT and we are getting mostly snow now, but I think it is definitely an issue. Water should not be getting into that area and pooling out when you open the door. I will keep you posted when I bring it to the dealership.