I have 2 compartments in the rear that do not have drains. I get a washover when coming to a stop. I usually mitigate this with a tap on the gas but occasionally I still get some. I get some water in the compartments. I also get some if I'm out in the rain. Both of these hold batteries and chargers. I don't want to just open them up with a hole to drain. The back of the compartment is hard or impossible to reach with batteries in. Looking for best suggestions on flush mount one way drains or remote open/close valves, again flush mount.