GT World Challenge Europe Endurance Cup In 2021, Buus joined his regular team Allied Racing for three races, starting from the
24 Hours of Spa in the
GT World Challenge Europe Endurance Cup - Silver Cup, where Buus came ninth in his category, he came 14th at the
Nürburgring and 15th in the
Circuit de Barcelona-Catalunya. Buus rejoined the championship in
2024, competing with Lionspeed GP. He competed in the bronze category, and got one podium at the third round at the
Nürburgring. Buus retired from the final two races of the season at
Monza and
Jeddah, getting his maiden fastest lap in the latter. In the bronze category, Buus finished the championship in 19th with 20 points, and in the overall championship he didn't score a point, with his highest result being a 28th at the
Nürburgring.
Asian Le Mans Series Buus made his debut in the series for
Earl Bamber Motorsport in the
GT class of the
2023–24 season, where he partnered
Thai racing driver
Tanart Sathienthirakul, and
Indonesian racing driver Setiawan Santoso. He had a best result of 11th in the first round of the championship at the
Sepang International Circuit. He and his teammates came 29th in the championship.
Intercontinental GT Challenge Buus did three races in the
2024 Intercontinental GT Challenge, first in the
2024 Bathurst 12 Hour where he got his only podium after getting third in his category, he also drove in the
2024 24 Hours of Nürburgring, coming 13th in the race, but ninth in IGTC standings. Buus finished his season with an 11th place at
2024 Indianapolis 8 Hours. He finished the championship in 15th with 16 points.
GT World Challenge Asia Buus also completed in the
2024 GT World Challenge Asia with Phantom Global Racing for the first two rounds. He came fourth and 19th in the first round at the
Sepang International Circuit, and came 15th and seventh in the next round at
Buriram International Circuit. Buus returned to the series in the fifth round of the series at
Okayama International Circuit with Origine Motorsport. He came fifth and fourth in the races and got his first pole position in the second race. Buus came 17th in the drivers championship with 40 points.
Deutsche Tourenwagen Masters For 2025, Buus was set to compete in the
2025 Deutsche Tourenwagen Masters with Allied Racing, partnering
Ricardo Feller. However, the team shuttered its program prior to the start of the season. ==Personal life==