In 2001 Junqueira joined the CART Championship Car series driving for Chip Ganassi Racing where he had immediate success, capturing a win in his 14th race and finished second in points with two wins the following year. In 2003 Ganassi left to the rival Indy Racing League and Junqueira joined &lt;a href="Newman/Haas%20Racing"&gt;Newman/Haas Racing&lt;/a&gt;, the top team remaining in what was now the Champ Car World Series. He captured series runner up honors in both 2003 and 2004, capturing two wins in each of those seasons. He also drove in the Indianapolis 500 four times for both Ganassi and Newman/Haas in one-off appearances. In 2002, he qualified for the pole position, and he twice finished 5th in the race.