The 2004 IRL IndyCar Series season was dominated by two teams, Andretti Green Racing and Rahal Letterman Racing. While there was great parity in 2003 between Honda and Toyota powered teams, in 2004 Honda began to outshine Toyota bringing their teams Penske Racing and Chip Ganassi Racing down with it, leaving Scott Dixon winless and in 10th place in his attempt to defend his 2003 championship.
Season champion Tony Kanaan set a record by completing all 3,305 possible laps, the first IndyCar driver in modern history to do so. Taken from http://en.wikipedia.org/wiki/2004_IndyCar_Series_season.


The 2004 Champ Car season was the inaugural season for the Champ Car World Series. It began on April 18, 2004 and ended on November 7 after 14 races. The Bridgestone Presents the Champ Car World Series Powered by Ford Drivers' Champion was Sébastien Bourdais. The Rookie of the Year was A. J. Allmendinger.
The open-wheel racing organization CART, Inc. had operated until 2003. After that year's season, the series declared bankruptcy and was liquidated in an Indianapolis courtroom in January 2004. Three team owners who had participated in the CART series, Gerald Forsythe, Kevin Kalkhoven, and Paul Gentilozzi, purchased the series' liquidated assets and resurrected it as the Champ Car World Series for the 2004 season. Taken from http://en.wikipedia.org/wiki/2004_Champ_Car_season.