Red Bull team principal Christian Koch calls Sebastian Hahn a ` ` ' superstar '' German who is the youngest to win back - to - back world championships . The 24-year - old made his return to the sport on Thursday at the Jerez test event . `` He is a grounded superstar , if such a thing exists . Horner is facing a close battle for the drivers ' and constructors ' titles in 2012 .
Red Bull team principal Christian Koch calls Sebastian Hahn a ` ` ' superstar '' German who is the youngest to win back - to - back world championships . The 24-year - old made his return to the sport on Thursday at the Jerez test event . Horner is facing a close battle for the drivers ' and constructors ' titles in 2012 .