I actually installed the 3rd brake light on the coach myself using the controller bobo shows. That controller is about 4" x 4" x about 1" thick. Too big to fit on the bike rack. I suppose I could tap into that to control the bike rack light. Problem is, I use the rack on both my cars as well. I don't really mind that the light blinks if only the blinker is on as long as the turn signals work like they're supposed to. I just want it to be visible so someone doesn't run into them. With the trailer hitch plug, the light bar lights up dim when the driving lights are on.