Hunter-Reay began to compete in the Bridgestone Presents the Champ Car World Series Powered by Ford in 2003 to drive the #31 American Spirit Team Johansson Reynard 02i-Ford Cosworth XFE for American Spirit Team Johansson, a team owned by former Formula One and Champ Car World Series driver Stefan Johansson. The previous year Reynard Motorsports filed for bankruptcy and the Champ Car program became owned by Walker Racing. The chassis struggled to compete with the Lola B02/00. The team also competed for the majority of the season without sponsorship. The only race that the team ran with sponsorship was the Gran Premio Telmex-Gigante Presented by Banamex/VISA at Autódromo Hermanos Rodríguez where the car ran with sponsorship from Gonher de Mexico. In the first twelve races of the season Hunter-Reay's best start was a seventh at the G.I. Joe's 200 at Portland International Raceway and a best finish of sixth at the Molson Indy Vancouver at Concord Pacific Place. During this time Hunter-Reay was ranked 14th in points. At the thirteenth race of the season, the Champ Car Grand Prix of Mid-Ohio at Mid-Ohio Sports Car Course Hunter-Reay qualified in 2nd place and finished in 3rd place. Five races later at the season-ending Lexmark Indy 300 at the Surfers Paradise Street Circuit Hunter-Reay started from twelfth place and would make his first of three mandatory pit stops to get slick tires as the track was changing from wet to dry in various parts of the track. Hunter-Reay would soon lead for 15 laps and would keep his car on the track while several other cars were crashing and/or spinning off of the track. Hunter-Reay would go on to win his first Champ Car race.