Possible Clues:

• High-speed supercharged motor-racing vehicle
• Racing body with an annual "500" event
• __ Series: auto races
• 2005 17-race series
• Single-seater with turbocharged rear engine
• US motor, lead-free sort, lively when climbing
• Spirited driver's first with a lot of speed turning up in this?
• Big series name in auto racing
• "500" race-sanctioning group
• Race-sanctioning biggie