This is exactly the reason I didn't go with a 50" single row on the roof. After doing the (2) 10" I really don't see myself having a need for that much light. I am not driving deserted stretches of road or trail at speed and you can't use it on the highway, without blinding everyone. I bought a couple flush mount D2's to use as backup lights to be cut into the wind deflector in the rear but I have decided against that idea too because it would blind other drivers. So I think I will do (4) D2 diffused at the corners of my roof rack for campground lighting and call it done.
I am running D2 wide beams for rear lighting. They are blinding but do put out plenty of light. I have a set of D2 driving that I am selling. If they dont sell then I will use add as side lighting.