This is what the Guinness Book of Records says. The symbol of Citroen was shining in six colors, the letters were 20.8 meters in height, and 90 km of wires were used to light 250,000 lamps. The advertisement could be seen from a distance of 38 km, and no wonder: it was mounted on the Eiffel tower. It would shine forever, if it weren’t for the Great Depression that brought Citroen’s business (and himself) down: the ad was taken off in 1936. But Citroen’s lamps kept shining for the Parisians: Citroen donated them for the illumination of the Arc de Triomphe and the Place de la Concorde.