Nico Rosberg completed the first few laps with the new Mercedes F1 W04 this morning at Jerez in Spain.

Unusually, the initial shakedown runs were conducted a few hours before the official 'unveiling', with Rosberg and new team-mate, Lewis Hamilton, taking the covers off the latest Silver Arrow at around 13.35 hours CET.

Speaking after the launch, Rosberg said the whole team is feeling 'very positive' and 'highly motivated' for the coming season. The German also added that he is looking forward to working with Hamilton and that he has been busy getting himself in shape for F1 2013 in recent months.

"I've been working really hard over the winter on my physical preparation, both in the mountains - climbing to over 2,000 metres with ski boots - and also in the Mediterranean, training on my bike, swimming and running," confirmed Nico, who of course last year took the first victory for a works Silver Arrow in the modern era.

"I fitted all that training around regular visits to see the guys at the factory in December and January and we have done some really good work, especially in the simulator.

"The car seems to be performing well in the virtual world but we have a very busy and intense programme ahead of us during testing to make sure we can deliver that performance on track.

"The atmosphere in the team is very positive and the people are highly motivated to succeed.

"And, of course, I have a new team-mate with Lewis. It's his first time in the Silver Arrow and I look forward to working together and pushing each other hard, to make this the best team in F1."