I also have exacltley the same problem with my 03 fabia. Carpets not wet so could not figure out what the problem was. Tried to remove the rear door trim but struggled. Have had a bad problem with condensation and also some mold on the seats.
I am better taking this to the dealer to sort rather than trying to solve the problem? it is out of warranty but as it is a known issue will they still fix it. Had similar porblem with my scenic known issues with the pencil coils and they fixed for free out of warranty.
