At the end of the 2015 Autobacs Super GT Series, it was the reigning GT500 champions at NISMO who successfully defended their title following a thrilling season finale at Twin Ring Motegi. Drivers Tsugio Matsuda and Ronnie Quintarelli fought back from twelfth on the grid to finish second in the 250km final race at Motegi, good enough to overhaul their championship rivals, Calsonic Team Impul, and their drivers Hironobu Yasuda and J.P. Oliveira, by five points - as the Calsonic GT-R fell just short of the title with a fourth-place finish. The race win went to the KeePer TOM's Lexus RC-F of Andrea Caldarelli and Ryo Hirakawa, who took their second win of the year thanks in large part to some incredible daredevil maneuvers in traffic by the 21-year-old Hirakawa in his closing stint of the race. Third place in the race, and the championship as well, was the Raybrig Team Kunimitsu Honda NSX of Naoki Yamamoto and Takuya Izawa, who picked up a popular result at one of Honda's two "home circuits." It was a landmark moment for Italian driver Ronnie Quintarelli, who became the first four-time GT500 champion in history with his successful defense of the title. The 36-year-old from fair Verona surpassed three-time champions Masahiko Kageyama, Satoshi Motoyama, Juichi Wakisaka, and Yuji Tachikawa as the most successful driver in Super GT history. For Tsugio Matsuda, who represented Nissan at this year's 24 Hours of Le Mans, it is his second GT500 championship in as many years. Matsuda will enter 2016 in a three-way tie with Motoyama and Tachikawa for the lead in career victories - they have sixteen wins each. NISMO, the most successful team in Super GT, have now won their eighth championship, and become the first team to successfully defend the GT500 championship since they themselves did it in 2003-04. The Nissan GT-R enjoyed a successful 2015 season on the whole, with GT-Rs winning four out of eight races in both the GT500 and GT300 categories, including two dual 1-2 finishes at Fuji Speedway and Autopolis. The championship in the second-tier GT300 category had already been decided before the last race - for the Gainer Tanax Nissan GT-R of Macanese veteran Andre Couto. Couto won his very first Super GT championship in the penultimate round at Autopolis two weeks ago. Bathurst 12 Hour hero and Blancpain Endurance Series champion Katsumasa Chiyo, and 23-year-old rookie Ryuichiro Tomita, split co-driver duties throughout the season alongside Couto. They helped drive the team to victories in the series' two biggest races - the Fuji 500km in May, and the International Suzuka 1000km in August. An emotional Couto dedicated the championship to his team, his two young co-drivers, and to the memory of his late son Afonso, who died in 2010 after a lengthy battle with leukemia. The final win of the GT300 season went to the apr Toyota Prius GT of Koki Saga and Yuichi Nakayama, in what proved to be the last race for the V8-powered, mid-engined Prius before its retirement from competition. The ever-popular Hatsune Miku SLS of Goodsmile Racing, and drivers Nobuteru Taniguchi and Tatsuya Kataoka, finished second in their last race as the outgoing GT300 champions, ahead of the second Gainer team car - the Mercedes-Benz SLS of Katsuyuki Hiranaka and Bjorn Wirdheim. A very special thanks goes out to NISMO TV and Radio Le Mans, who collaborated to broadcast the entire 2015 season for the global audience. All eight races of the 2015 Super GT season may be viewed in perpetuity on the official NISMO YouTube channel.