I agree that having something taller on the rear of the toad will make it more visible as they will see there is a continuation of something behind the rv. It's also been shown in studies that for some reason RED is one of the colors not seen most by other drivers along with tan, silver and white. I'd try those flexible little pole things with the orange flags on time - mounted on the rear bumper. If someone is waiting to make a left hand turn after you pass, they probably can't see all the signs, lights etc because the rv blocks the view. They should however be able to see the higher orange flags on the rear.