I don't have an SD but a D. I imagine the doors have similar drain holes. There is a place along the inside bottom that can get clogged with debris. You should be able to stick a toothpick or popsicle stick up there and clear it out. If I had standing water sloshing around in my door, I would remove the inside panel and clean out the debris from the inside and dry the door out thoroughly with a hair dryer. If there is any rust starting, you can treat it before it gets worse. There are rust neutralizing products available but I am not an expert on this subject so will leave it to the more experienced members of the forum to comment.

I don't believe there are any drain holes in the floor. You should not be getting water in the cabin. You should try to identify the source. Is it in the front or back or both? Maybe you have a windshield leak.

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