|Hildebrand and Servia are both candidates to compete in Formula E|
IndyCar racer and new Rolex 24 winner Sebastien Bourdais (LEFT) and Ex-Formula 1 driver Bruno Senna are among the latest group of drivers to express interest in contesting the inaugural Formula E season.
The Frenchman, who co-drove the Action Express Corvette DP to the overall win at the weekend, has signed up, along with his current IndyCar rivals Oriol Servia and JR Hildebrand.
Brazilian Senna, who switched to sports cars with Aston Martin last year, is one of 16 drivers who have now put themselves forward for seats in the FIA's new all-electric series.
Others on the new list include sometime grand prix racers Narain Karthikeyan, Christijan Albers and Franck Montagny, and GP2 driver Daniel Abt.
The initial batch of interested drivers revealed by the championship earlier this month included Sebastien Buemi, Karun Chandhok, Lucas di Grassi, Tonio Liuzzi, Takuma Sato and Marco Andretti.
Although driver signing decisions will remain down to the individual Formula E teams, the series has established a "Drivers' Club" scheme to draw up a list of potential candidates, all of whom will have early opportunities to test the championship's Spark-Renault car.
Ex-F1 names Super Aguri and Virgin are among the 10 teams committed to the 2014/15 series, alongside IndyCar front-runner Andretti Autosport, a collaboration between four-time F1 champion Alain Prost and DAMS, and a partnership between sportscar firm Venturi and actor Leonardo DiCaprio.
Formula E's first race will take place in Beijing on Sept. 13 this year.
Formula E Championship – Drivers' Club lineup:
Daniel Abt (GER)
Christijan Albers (NLD)
Marco Andretti (USA)
Sebastien Bourdais (FRA)
Sebastien Buemi (CHE)
Karun Chandhok (IND)
Lucas di Grassi (BRA)
JR Hildebrand (USA)
Ma Qing Hua (CHN)
Narain Karthikeyan (IND)
Vitantonio Liuzzi (ITA)
Franck Montagny (FRA)
Takuma Sato (JPN)
Bruno Senna (BRA)
Oriol Servia (ESP)
Adrien Tambay (FRA)