My tray had such a small hole I did not detect it at first or even second study. Poke around esp on the areas where the battery footprint rests. I had a very small hole (less than millimeter) once I scraped away loose rusty flakes of metal. Enough to fill rear footwell and soak front passeger mat.

Great idea!

I have the same thing going on but on a much smaller level. One thing I noticed is that when I open the passenger door, a bunch of water pours out of the door jam (no man's land between carpet trim piece and bottom portion of the door seal. I've deduced that either the top of the door seal is bad and all that water that sloshes out isn't supposed to be there, or all that water is draining from somewhere (what gets past the window scraper and goes inside the door) and isn't exiting past the door seal for whatever reason. Likely not your same issue, but its worth a look. I don't get a puddle in the back passenger foot well, but its a good amount of moisture.

Think these cars were just meant to leak. Went outside yesterday after a pouring rain and found INCHES of standing water in the butt-shaped bucket where my rear seats would be if I had them. If I wasnt worried about piercing the galvanizing layer, I'd just drill a hole at the lowest point and stick an easily removeable grommet or a draincock in it.