Turner Motorsport won the 2003 and 2004 Speed World Challenge Touring Car Championships, breaking an eight year Honda / Acura domination of the series. After winning the championship the second consecutive time, Turner Motorsport left World Challenge to race in the 2005 Grand-Am Cup season. In their first full year in the series, Turner finished second in class in both the Street Tuner (ST) and Grand Sport (GS) classes. Turner Motorsport won both the 2006 Grand Am Cup GS and ST Driver and Team Championships and the 2007 Grand Am Cup ST Championship. Turner Motorsport was the first team to win dual GS and ST driver and team championships in the same season.