A similar situation exists with turn signals. Some models didn't come from the factory with turn signals so accessory units were allowed and encouraged (for safety purposes) in judging. But there is an extra consideration here because many accessory turn signals didn't integrate with the park lights and brake lights (4 wire vs 7 wire) so extra lamps had to be installed. Fred's simple rule was "As it came from the factory" conflicts with the emphasis on safety and driving the cars.