WTCC
In 2005, the ETCC became the World Touring Car Championship (WTCC). Peter Terting replaced fellow German Diefenbacher. Jason Plato also joined the team for four rounds, and Marc Carol for one round. Later in 2005, the León model made its debut.
In 2006, Gabriele Tarquini, Yvan Muller and James Thompson joined the team. André Couto, Oscar Nogués and Florian Gruber also raced in one-off rounds.
In 2007, Rydell, Thompson and Terting left the team and were replaced by Michel Jourdain Jr. and Tiago Monteiro. Terting and Rydell later made one-off appearances for the team, as did Nogués. Towards the end of the season SEAT debuted the TDi diesel version of the León.
In 2008, Jourdain left the team, as the team scaled down from a six-car to a five-car team. Yvan Muller won SEAT's first driver's championship in the WTCC and SEAT also won the manufacturers title.
In 2009, SEAT Sport continued with the same five drivers, with French team Oreca assisting with the operation. Gabriele Tarquini won SEAT's second in-a-row driver's championship in the WTCC and SEAT won the manufacturers title for a second consecutive year.
After winning two consecutive driver's and manufacturers titles, SEAT withdrew from the WTCC at the end of the 2009 season as a manufacturer-backed team. However, in January 2010, it was announced that they would provide backing to the newly formed SR-Sport team run by SUNRED Engineering, while also confirming Gabriele Tarquini, Jordi Gene, Tiago Monteiro and Tom Coronel as 2010 drivers, as Yvan Muller departed for the works Chevrolet team.
For 2012, SEAT announced that they will return to the WTCC Season as a Customer Supply team, SEAT Sport supplied engines in 2012 to the Lukoil Racing Team who run two 1.6T cars driven by veteran SEAT Driver Gabriele Tarquini and Aleksei Dudukalo. They also supplied 1.6T Engines to the Tuenti Racing Team who ran cars for Pepe Oriola and Fernando Monje, Tuenti Racing Team driver Tiago Monteiro ran a SEAT Sport TDI engine for the first weekend but then switched to a 1.6T engine supplied by SUNRED. Special Tuning Racing have run both a 1.6T engine and 2.0 TDI engine both supplied by SEAT Sport, Daryll O'Young has only used the 1.6T engine but Tom Boardman used the 2.0TDI from the start of the season till round 7. SUNRED engineering ran a SEAT Sport 2.0TDI engine at the start of the season in Andrea Barlesi's car but then switched to the SUNRED 1.6T engine from rounds 2-3.
BTCC
Between 2004 and 2008, SEAT Sport competed in the British Touring Car Championship, under the SEAT Sport UK banner. Jason Plato drove for the team for five years, while Rob Huff, James Pickford, Luke Hines, Darren Turner, James Thompson and WTCC regular Tom Coronel (as a one-off) also competed. Initially the cars were run by RML Group until they began concentrating on the Chevrolet WTCC project. Plato finished as championship runner-up in 2006 and 2007. In 2008 the TDi version was used, but reliability was a problem. Two teams continued to campaign petrol SEATs in the championship during 2009 with Adam Jones and series returnee Dan Eaves competitive for the Cartridge World Clyde Valley team, while Gordon Shedden drove for Clyde Valley for a couple of events before it withdrew, but he returned to drive a Leon for the Club Seat outfit.
In 2010, Tom Boardman drove a petrol SEAT Leon Under the team name Special Tuning UK with sponsorship from Club SEAT. Phil Glew joined Tom in a SEAT for one weekend at Silverstone racing under the team name of YourRacingCar.com but the car was run by Special Tuning UK.
In 2011, Boardman and
