He competed for Nissan Motorsports in the top LMP1 class of the 2015 FIA World Endurance Championship, but the team withdrew from the series after one race because of a very uncompetitive car.[6] Mardenborough serves as a co-producer, stunt driver and consultant on the movie, which depicts his early career and personal life, and gave permission for the filmmakers to include his 2015 crash at the Nürburgring Nordschleife, which killed one spectator.[12] During a gap year, he noticed an online time trial for the GT Academy competition on Gran Turismo 5 and decided to make a serious attempt at qualifying for the event, which offered a professional racing contract with Nissan to the overall winner.[15][16] Jann Mardenborough took part in the 2011 GT Academy competition,[17] which was a joint venture between Nissan and the developers of "Gran Turismo" with the goal of identifying potential racers via online racing events.[19] Driving alongside fellow GT Academy winners Lucas Ordóñez, Jordan Tresson and Bryan Heitkotter, he finished third in his class and 26th overall.Mardenborough made his debut at the 24 Hours of Le Mans in 2013, driving a Zytek Z11SN-Nissan for Greaves Motorsport alongside Lucas Ordóñez and Michael Krumm in the LMP2 class.[37] In 2015, Mardenborough was selected as one of the drivers for Nissan Motorsports' entry into the top LMP1 class of the FIA World Endurance Championship (WEC), which includes the 24 Hours of Le Mans.[43][44] On 28 March 2015, during a one-off outing in the VLN series, his GT3-class Nissan GT-R Nismo caught air at the Flugplatz section of the Nürburgring Nordschleife.[45] Mardenborough's achievements and growing global profile led to Sports Pro Media naming him 50th on their 2015 list of the 50 most marketable athletes in the world.[47][48][49][50] His Japanese F3 campaign with B-Max Racing saw him claim four wins and eight additional podiums to finish runner-up to future Super GT GT500 champion Kenta Yamashita by three points.[53] He and teammate Hironobu Yasuda finished 15th in the 2017 GT500 standings, with a best result of fifth, but they had been in contention for victory at the penultimate round at Buriram until a slow pit stop dropped them to third and then car problems with two laps to go forced them to retire.He had passed the Team Kunimitsu Honda NSX-GT of Naoki Yamamoto and Jenson Button for the lead during the opening stint, but overheating issues caused by grass picked up in an off-track excursion by Sasaki limited the pair to third.[64] Despite often being faster than his teammate, Mardenborough was not retained by Nissan for the 2021 season, making way for seven-time Formula 2/GP2 race winner and former Honda junior Nobuharu Matsushita.[13] In May 2023, he made a return to racing at the Fuji 24 Hours round of the Super Taikyu Series, driving Helm Motorsports' Nissan GT-R Nismo GT3.[67] Mardenborough contested the Silverstone 500 round of the 2024 British GT Championship with the McLaren 720S GT3 Evo of Team RJN, claiming a win in the Pro-Am class and an overall podium alongside Chris Buncombe.