In June 2017, Boonen was awarded his motor racing licence after passing the required tests. The following month he made his car racing debut in the Volkswagen Beetle-based Fun Cup, competing in the 25 Hours of the VW Fun Cup at the Circuit de Spa-Francorchamps: he and team-mates Anthony Kumpen, Bert Longin and Ruben Van Gucht finished in 29th place out of 118 starters, 15 laps down on the winning team of Cédric Bollen, Fred Caprasse, Guillaume Mondron and Fred Bouvy.