Racer X was the alternate identity of Jean-Pierre Vaillant during the 1960 racing season. This mysterious driver caused a lot of headaches for Team Vaillante, easily setting better times than any of the other Formula 1 teams in a car that no one knew of. Racer X has employed two engineers to help him fix his car. However, no one seems to be able to understand their language, only adding to the mystery surrounding the man.
At the race of Gueux, Michel Vaillant crashed while trying to overtake Racer X. Racer X then mysteriously let the Russians in their Zvezda's win the race, even though he was able to beat them soundly. Afterwards he revealed his identity to Team Vaillante: it was Jean-Pierre Vaillant himself, having used a few tricks to keep his identity concealed. Reasoning to his family that his father stubbornly refused the creation of a new Formula 1 car while every other racing team did innovate, he had to take some drastic measures to prove to him that it was necessary to innovate if Team Vaillante was to win any future races. He then revealed the mystery car was actually a Vaillante, with Jean-Pierre confessing that the Russians won because they were just better racers than he was; not because of the car.
After the next race, Racer X suddenly is seen driving in a Ferrari, with no one at Team Vaillante knowing anything about it; Jean-Pierre is standing next to them. After the Ferrari enters the pitlane, it is revealed to be Agnes Vaillant, working together with Ferrari to give Jean-Pierre some of his own medicine.
Throughout the rest of the series, the situation surrounding Racer X is often quoted; evidently, it left a deep impression on the family. It also proves that Jean-Pierre is willing to go to great lengths to show the world the superiority of Vaillainte.