There is no fixed definition of the number of vehicles or the amount of modification allowed outside of motorsports. There are no national regulations or laws that determine what is or is not a production vehicle. By 2011, the "Guinness Book of Records" listed the Bugatti Veyron as the world's fastest production car. But only five of this version were made. In 2013 their decision was appealed on the ground that the Bugatti was a modified versionGuinness upheld the appeal and initiated a review of their production car definition. The outcome of the review was that the Bugatti record was reinstated. Guinness were also reported in some sources as saying that at least 50 identical vehicles were needed to be made to constitute a production car. In February 2014, "Road and Track" wrote that Guinness required 30 identical vehicles.