"It's exactly the same colour scheme, so some of you might look at this and go 'Ahh looks kind of similar to last year,' but I tell you this is completely different to last year," said Button. "Under the skin it is so, so different."
"As Jenson said, the car might look similar with the colours, but it's a big project that the people here have worked day and night for it, and I think we've got a very strong car," agreed Perez.
"We all know the regulations haven't changed much since 2012, but they've changed enough to make a difference," Button continued. "We've taken a good approach to this season; obviously the future is very different F1 in terms of 2014 and the regulations, but you go into this season aiming to win the world championship and this is exactly what we're doing in 2013."
Agreeing that the MP4-28 was a natural evolution of last year's chassis design, Button added: "We don't 'hope' - because we know how much hard work has gone into this - that we're going to be fighting for [the championship]. We're just really excited."