McLaren's Hamilton and Button raring to go as MP4-27 unveiled

Speaking at the launch of McLaren's new car for 2012, Lewis Hamilton tells BBC Sport's Jake Humphrey he has "matured" following a difficult 2011 season and "nothing else matters" apart from winning his second world championship.

Hamilton, the 2008 world champion, believes the new MP4-27 looks "beautiful", while team-mate Jenson Button speaks of his excitement and apprehension ahead of driving the new car for the first time.