first season - the Audi R8R (open-cockpit 'roadster' prototype) and the Audi R8C (closed-cockpit 'coupé' GT-prototype). The R8R scored a credible podium on its racing debut at Le Mans and was the concept which Audi continued to develop into the 2000 season due to favourable rules for open-cockpit prototypes. However, most of the competitors (such as BMW, Toyota, Mercedes and Nissan) retired at the end of 1999. The factory-supported Joest Racing team won at Le Mans three times in a row with the Audi R8 (2000–2002), as well as winning every race in the American Le Mans Series in its first year. Audi also sold the car to customer teams such as Champion Racing. In 2003, two Bentley Speed 8s, with engines designed by Audi, and driven by Joest drivers loaned to the fellow Volkswagen Group company, competed in the GTP class, and finished the race in the top two positions, while the Champion Racing R8 finished third overall, and first in the LMP900 class. Audi returned to the winner's podium at the 2004 race, with the top three finishers all driving R8s: Audi Sport Japan Team Goh finished first, Audi Sport UK Veloqx second, and Champion Racing third. At the 2005 24 Hours of Le Mans, Champion Racing entered two R8s, along with an R8 from the Audi PlayStation Team Oreca. The R8s (which were built to old LMP900 regulations) received a narrower air inlet restrictor, reducing power, and an additional of weight compared to the newer LMP1 chassis. On average, the R8s were about 2–3 seconds off pace compared to the Pescarolo–Judd. But with a team of excellent drivers and experience, both Champion R8s were able to take first and third, while the Oreca team took fourth. The Champion team was also the first American team to win Le Mans since the Gulf Ford GTs in 1967. This also ends the long era of the R8; however, its replacement for 2006, called the Audi R10 TDI, was unveiled on 13 December 2005. The R10 TDI employed many new and innovative features, the most notable being the twin-turbocharged direct injection diesel engine. It was first raced in the 2006 12 Hours of Sebring as a race-test in preparation for the 2006 24 Hours of Le Mans, which it later went on to win. Audi had a win in the first diesel sports car at 12 Hours of Sebring (the