19 Audis Aspen Tdi Clean Diesel Dinner Stock Photos, High-Res Pictures, and Images - Getty Images

Juan Bollini, Melissa Ganzi, Zac Efron and Kris Kampsen attend Audi's Aspen clean diesel event on December 20, 2009 in Aspen, Colorado. Get premium, high resolution news photos at getty

47 Audi R8 Tdi Stock Photos, High-Res Pictures, and Images - Getty Images

47 Audi R8 Tdi Stock Photos, High-Res Pictures, and Images - Getty Images

Audi a4 1 9 tdi hi-res stock photography and images - Alamy

Audi a4 1 9 tdi hi-res stock photography and images - Alamy

47 Audi R8 Tdi Stock Photos, High-Res Pictures, and Images - Getty Images

Audi a4 tdi hi-res stock photography and images - Alamy

19 Audis Aspen Tdi Clean Diesel Dinner Stock Photos, High-Res Pictures, and Images - Getty Images

19 Audis Aspen Tdi Clean Diesel Dinner Stock Photos, High-Res Pictures, and Images - Getty Images

47 Audi R8 Tdi Stock Photos, High-Res Pictures, and Images - Getty Images

47 Audi R8 Tdi Stock Photos, High-Res Pictures, and Images - Getty Images

47 Audi R8 Tdi Stock Photos, High-Res Pictures, and Images - Getty Images

47 Audi R8 Tdi Stock Photos, High-Res Pictures, and Images - Getty Images