Martinez for debut

Martinez, 25, will drive a third car for the team in addition to their usual two after signing one-race deal with the 2003 champions.

Martinez said: "I'm very happy, this is a dream come true! Being able to make my Champ Car debut with one of the best teams in the world is incredible.

“And what better place to start off this new stage of my life than in Mexico where everybody has supported me so much.

“I want to thank (team boss) Jerry Forsythe and his Team for believing in me, I know it's not going to be easy but I've been waiting for a long time for this great opportunity and I'm going to make the most of it.”

Martinez' debut comes after two years in the ChampCar Atlantic Series in which he has finished fifth overall in both 2005 and 2006. He has also previously driven in A1GP and in the Formula Renault V6 Eurocup.

Martinez will partner team regular Paul Tracy and newcomer Buddy Rice in Mexico City.