Despite a pole at Phoenix, the association was unsuccessful, with Herta managing only a 20th place in the series standings while his teammate Jimmy Vasser finished 8th.

At the height of Herta's career, fan interest in the Shell-sponsored driver was dubbed "Hertamania" by team owner David Letterman.

In the opening laps of the 1998 event at Elkhart Lake, Wisconsin's Road America circuit, Herta was involved in a major accident.

In the 4-mile (6.4 km) road course's fifth turn, Herta got too close to the back of the car of co-owner Rahal, and spun out into a paved runoff area, facing oncoming traffic.

[citation needed] After dabbling in sports cars, he revitalized his open-wheel racing career by substituting for an injured Dario Franchitti halfway through the 2003 IRL season.

On July 31, 2005, Herta took his second IndyCar Series win, defeating AGR teammate Dan Wheldon in a close finish in the Firestone Indy 400 at the Michigan International Speedway.

In early 2006, he drove at Mazda Raceway Laguna Seca and Fundidora Park for A1 Team USA in the A1 Grand Prix series before returning to Andretti Green for the IRL season.

In 2011 the team fielded a car for Dan Wheldon in the 2011 Indianapolis 500 which resulted in a stunning victory, and a full-time entry in Indy Lights for Duarte Ferreira.