Water in the battery compartment

[boyhamdzui]

On a beautiful day in FL after raining for so many days, I opened my trunk and saw some water under the hollow plastic piece (where the tow hook is). I try to scoop the water out thinking I'm the one who spills the water. However, the water kept filling back up. I removed that piece completely and saw a pool of water half way fill my battery compartment . I have to remove some blind plugs to excavate all the water, reinstall them and watch for a few days. Rain came back (basically everyday in FL summer). I checked it daily since then and found little water built up each day. I checked taillight, trunk seal and everywhere on top of the trunk, no sight of water. Only one place that has water trail is #1 (the hollow rail in the side) in this picture https://www.realoem.com/bmw/enUS/sho...diagId=41_2125. I wonder if anyone can give me any suggestions? I think it could be a drainage clogged somewhere but don't know specific location.

[Russbmw]

Not sure on specifics, but I've had BMW's for about 20 years or so, and whenever there's water leaking into the boot it has been from the rear light seals

[boyhamdzui]

I finally found the leak, if anyone has the same issue you may check this spot too