`` He is a great champion and a great ambassador for the sport , '' Horner told F1 's official website . ` Red Bull team principal Christian Horner calls Sebastian Vettel a `` grounded superstar '' German driver is the youngest to win back-to-back world championships . The 26-year-old has won three of his last four races and he will be hoping for another victory in Sunday's race at Silverstone. Horner is predicting a close battle for the drivers ' and constructors ' crowns in 2012 .
Red Bull team principal Christian Horner calls Sebastian Vettel a `` grounded superstar '' German driver is the youngest to win back-to-back world championships . The 26-year-old has won three of his last four races and he will be hoping for another victory in Sunday's race at Silverstone. Horner is predicting a close battle for the drivers ' and constructors ' crowns in 2012 .