got this on my tolly it looks like its the seal thats fitted to the door at the bottom
i cleaned the seal thats fitted to the car and the paint at the bottom of the door and that lessen'd the
problem
but if you look at the seal on the door you will see that it covers the door drain holes the seal has cut outs for the water to run throught but as mine there blocked with a slimey gunge so the water fills up in the door then runs out through the door trim panel above the car seal in to the car
i think if you give the seals a good clean the
problem will stop as the water will be able to run away as it was designed to