Not had a carrier in quite a long time. I just used to hang the bicycles first, then sit the trailer board atop the hangers then tie it through the bicycle frames - looping the rope inboard of the lights to keep it in position.Please can someone advise me the safest and straightforward way to attach the lighting board to the back of the bike carrier? Ours is a towbar-mounted 2 prong carrier for 2 bikes.