UKPassats

Hi, got a 2019 R-Line Passat Estate B8. Recently noticed after heavy rain that when i open the boot - water comes from within the boot trim(door card), i've taken the trim all off now and the electic cabling to the heated windscreen on one side is very wet - any ideas on where the water might be getting in? I was thinking it might be from the side boot window trims as they appear to not be sitting down as flush as they should be?
and

Any ideas?