Formula 1 - Jenson Button and Sergio Perez on new McLaren

McLaren's Jenson Button says their new car for 2013 is "very different" underneath the bodywork following the official launch of the MP4-28.

The 2009 world champion believes the team are "in a good place" ahead of pre-season testing, while his team-mate Sergio Perez insists he is aiming to win the championship outright in his first season with the team after signing from Sauber.

Despite their pedigree, the Woking-based outfit have not won a constructor's championship since 1998, finishing third in the 2012 standings behind champions Red Bull and Ferrari.