I discovered a big pool of water in the driver side rear footwell a couple of weeks ago. Lifted carpet to get as much water out as possible and to try and dry it out - it's getting there, but periodically gets wet again with a few small pools of water.

The door seals look OK but I noticed today that the black rubber fitting covering the electrics box that you can see when you open the door was completely loose. Might it have been coming in through there? I have pushed it back in!

The water only appears in that foot well, nowhere else. The carpet is currently raised and the small pools of water are located on the metal floor. Still very wet up towards the seat where the carpet is tight to the floor. Any ideas?