"No, at my age, I'm still learning every day," said the son of longtime racing star Bobby Rahal. "It's not my time to be the go-to guy — not yet."

The 18-year-old rookie was put in the position of answering questions about his leadership abilities when it was confirmed last week that Sebastien Bourdais, his teammate on Newman/Haas/Lanigan Racing, will leave for Formula One at the end of the season.

The 28-year-old Frenchman will finally get this shot at the international series that he grew up longing to race in, and Champ Car will begin the process of trying to find a driver to fill the void left by the departure of its biggest name.

Barring unexpected problems over the last five races of this season, Bourdais will win an unprecedented fourth straight series championship. After winning Sunday at Road America, and with the Champ Car series now heading to Europe for new races in Holland and Belgium, Bourdais has a 37-point lead over Dutch rookie Robert Doornbos.

But that's only one example of how dominating Bourdais has been since coming to America in 2003 with a great racing resume from Europe's development ladder but virtually no recognition on this side of the Atlantic.

It was quickly apparent Bourdais was something special when he won the pole in his first race and went on to four more poles and three wins on the way to finishing fourth and taking rookie of the year honors.

Since then, he has been all but unbeatable, winning three straight titles.

Bourdais has won 28 of 69 career starts in Champ Car, along with 29 poles. He also proved his versatility in 2005 when he competed in the International Race of Champions series, winning against some of the best in NASCAR at Texas Motor Speedway to become the first Champ Car driver in 10 years to win in all-star series.

Nextel Cup star Mark Martin, who went on to win a record fifth IROC title that year, was so impressed with Bourdais, he said, "I'd put him a Cup car right now. That kid is amazing. He is a great race driver."

That comment got some rare national headlines for a Champ Car driver. With Bourdais now leaving, the struggling series is in deeper trouble than ever.

While series officials try to put on a happy face with talk of upcoming big announcements on the sponsorship front and new and exciting races overseas, there seems little to sell now to the American public.

Rahal, whose father won three open-wheel championships and the 1986 Indianapolis 500, could eventually become a big star. But he has yet to win a race and there is little else to build on at this point.

Former series champion Paul Tracy — the next biggest name in the series — is 38 and hasn't been consistently competitive since 2005.

The racing is still exciting and there are plenty of good drivers in Champ Car, but most of them are European and Brazilian and remain virtually unknown to the American public.

With Champ Car — formerly CART — struggling with minuscule TV numbers, a dearth of sponsorship money for the series and its teams, and almost no recognition for its drivers, losing Bourdais is a major blow.

The only statement from Champ Car came from CEO and president Steve Johnson, who said the series will "celebrate Sebastien's career" at its season-finale on Dec. 2 in Phoenix.