In 2004, Matsuura was the
Bombardier Rookie of the Year, finishing fourteenth in points. He was also the 2004
Bank One Rookie of the Year for the
2004 Indianapolis 500. In 2005, Matsuura again drove for Super Aguri Fernandez Racing, and again finished fourteenth in the Championship with a best place finish of 6th in the two road course races. He continued with the team in 2006 and finished a career best thirteenth in points with a best finish of 6th. For 2007,
Autobacs Racing Team Aguri switched allegiance to
Panther Racing, teaming Matsuura with
Vítor Meira. During the
2007 IndyCar Series season, Matsuura retired from six of the first eleven races and finished no better than eighth in the others. His struggles prompted speculation from media and fans that he might be dropped by
Panther Racing, culminating on July 20, 2007, when
Speed TV posted an article on its website stating that Matsuura would be immediately replaced by
Autobacs Racing Team Aguri Indy Pro Series driver
Hideki Mutoh. While the report was incorrect and the article has since been removed, it did little to stop speculation that Matsuura would be replaced following the 2007 season. On August 5, 2007, Matsuura matched a career best with a fourth place finish at the
Firestone Indy 400 at
Michigan. This prompted
Indianapolis Motor Speedway Radio Network play-by-play Mike King to suggest that the finish may help him stay in IndyCar Series for the 2008 season. The finish, however, only came in the aftermath of his avoiding a major back straightaway incident involving most of the front half of the field. For 2008, after longtime sponsors Panasonic switched their sponsorship to
Hideki Mutoh of the
Andretti Green Racing team in the IndyCar Series, Matsuura returned to Japan to compete in the
Formula Nippon Series. In August 2009,
Conquest Racing announced that Matsuura would drive for them at the 2009
Indy Japan 300 in a car sponsored by CLICK Securities Inc. Matsuura finished seventeenth for the part-time team. ==Motorsports career results==