Niki Lauda tips Sebastian Vettel to continue his title-winning success . German driver says the German will leave Red Bull in future . Sebastian Vettel 's contract with the constructor is set to expire at 2013 . Williams confirm Pastor Williams and Niki Lauda as drivers for 2013 .
Niki Lauda tips Sebastian Vettel to continue his title-winning success . Austrian driver says the German will leave Red Bull in future . Vettel 's contract with the constructor is set to expire at the end of 2014 . Williams confirm Pastor Maldonado and Valtteri Bottas as drivers for 2013 .