That Flash trailer is too neat

Bit of a tip, with mine I glued cut down pool noodles to the top of the timber rails that the boards sit on. I then got some noodles with the hole down the centre, cut this and put them on the vertical sides, just in case a board clipped that edge. something a bit more forgiving when you slide the gear in and out.
You dont have to use pool noodles, and looking at rail spacing it may be too thick but its what I had in the shed at the time.