Hello Arjen. I assume you’re talking about the front cover with the NACA duct. I made that. You can read about it here… (https://laidback.me/naca-duct-for-the-dfxl/). I don’t ride in the rain often but if I get caught in a surprise rain event, I can stick a rag or a piece of foam in the outlet of the duct. It’s not a great solution, but has only happened a couple of times.
Laid Back Log 
Nice! Just curious where you got the ‘hood’with air-vent inlet? How about rainwater, or simply change it with standard hood?
Hello Arjen. I assume you’re talking about the front cover with the NACA duct. I made that. You can read about it here… (https://laidback.me/naca-duct-for-the-dfxl/). I don’t ride in the rain often but if I get caught in a surprise rain event, I can stick a rag or a piece of foam in the outlet of the duct. It’s not a great solution, but has only happened a couple of times.