Some drivers have moved from F1 to racing in disciplines with fewer races during the season. The German touring car championship, the DTM, is a popular category involving ex-drivers such as two-time champion Mika Häkkinen and F1 race winners Jean Alesi, David Coulthard and Ralf Schumacher. In recent years, it has become common for former F1 drivers to take up factory seats driving LMP1 cars in the FIA World Endurance Championship, with notable drivers including Mark Webber, Allan McNish, Anthony Davidson, Alexander Wurz, Kazuki Nakajima, Sébastien Buemi and Fernando Alonso. A series for former Formula One drivers, called Grand Prix Masters, ran briefly in 2005 and 2006. Other drivers have moved to Formula E such as Nelson Piquet Jr., Sébastien Buemi, Bruno Senna, Jaime Alguersuari, Nick Heidfeld, Jarno Trulli, Jean-Éric Vergne, Felipe Massa, Stoffel Vandoorne, and more. Some drivers, such as Vitantonio Liuzzi, Narain Karthikeyan and Jos Verstappen went on to race in the A1 Grand Prix series. During its existence from 2008 to 2011, Superleague Formula attracted ex-Formula One drivers like Sébastien Bourdais, Antônio Pizzonia and Giorgio Pantano.