Hello Antoine 88
I had a similar issue. As you can make out from the pictures, I bent up a piece of stainless steel sheet to act as a gutter or trough. It is attached to the inside of the deck organizer with 4 screws. The trough traverses to gap between the traveller, deck organizer and dodger. These pics were taken today after many days of heavy rain. There was not even a drop of water on the sliding panel and nothing in the cabin at all. It works well!
I had a similar issue. As you can make out from the pictures, I bent up a piece of stainless steel sheet to act as a gutter or trough. It is attached to the inside of the deck organizer with 4 screws. The trough traverses to gap between the traveller, deck organizer and dodger. These pics were taken today after many days of heavy rain. There was not even a drop of water on the sliding panel and nothing in the cabin at all. It works well!