Matt Roberts presents live coverage of round 18 of the MotoGP Championship from Valencia. It is the final round of the 2013 MotoGP World Championship and the fight for the title is going down to the wire. Rookie Marc Marquez leads the championship with 13 points and is aiming to become the youngest rider to win the title since Freddie Spencer in 1983. Meanwhile, Jorge Lorenzo is looking to defend the title he won last year. Show less