 The following teams and drivers competed in the 2003 Champ Car World Series season.With the departure of Honda and Toyota to the Indy Racing League for the 2003 season, four CART teams joined them in the rival series as well.Chip Ganassi Racing, Andretti Green Racing (a merger of the former Team Green and Michael Andretti's Team Motorola) and Mo Nunn Racing became full-time IRL competitors for the 2003 season.