Mercedes has launched its new car - the W04 - during a filming day at the Jerez circuit.

The car was first seen as Nico Rosberg was driving on the circuit with new team-mate Lewis Hamilton taking photographs trackside as Mercedes announced a new partnership with BlackBerry. Following the morning's filming the car was officially launched by both drivers on the start/finish straight.

The new car makes use of the vanity panel to cover the stepped nose, while the team has also reverted back to Coanda-effect exhausts having ditched the system at the end of the 2012 season.

Having watched Rosberg behind the wheel all morning, Hamilton said he was looking forward to his turn driving the car in the afternoon.

"I am [excited] I could barely sleep last night!" Hamilton said. "It's quite an exciting day for us - the launch of a new car - and to be team-mates with Nico; we were just saying how crazy it is because we used to be team-mates back in 2000 when we were go-karting so it's a dream for me to be back here as his team-mate.

"It looks beautiful. It's a lovely car, I'm just excited to get in it ... I'm just really excited to get in and see what it feels like."

Red Bull has launched its 2013 car, the RB9, at its base in Milton Keynes.

The latest Adrian Newey-designed car features a stepped nose like last year's car but without the driver cooling slot, as well as a tightly packaged rear end. Newey said the car does have a vanity panel - a thin carbon fibre fairing that other teams have used to disguise the step - but that "it doesn't extend too far forward as then it doesn't justify it in weight".

He added: "This is very much an evolutionary car ... the devil has very much been in the detail"

The RB9 features a slightly tweaked colour scheme with purple sidepods to promote new title sponsor Infiniti. The Japanese car brand has upped its involvement with the team this year and occupies other sponsorship space on the nose, in front of the cockpit and on the rear wing.

The car will hit the track for the first time on Tuesday with Mark Webber at the wheel for the first two days of the Jerez test before reigning champion Sebastian Vettel takes over on Thursday and Friday. The team is hoping to continue its winning streak from the last three seasons after taking both drivers' and constructors' titles each year.

Sauber has become the latest team to launch its 2013 car, unveiling the C32 at its factory in Hinwill, Switzerland.

The car carries the hopes of new-recruit Nico Hulkenberg and rookie Esteban Gutierrez, who were both on hand to remove the covers. The C32 has some distinctive features such as a stepped nose that is masked from the side by a channelled vanity panel, but is still obvious when viewed from the front. It also has narrow sidepods which are notably slimmer than the Formula One norm, leading back to a coanda-style exhaust at the rear, which is clearly an evolution of last year's design.

In 2012 Sauber had its most successful year since its split with BMW, scoring four podiums with the C31 which was considered to be one of the better balanced cars on the grid. Without a technical director in place, the work on the new car has been headed by Matt Morris, chief designer, and Willem Toet, head of aerodynamics, while Monisha Kaltenborn starts her first full season as team principal.

Matt Morris explained: “The C31 was an extremely competitive car with many strengths. Our aim was to further improve these strengths and eliminate its few weaknesses.

“Over the course of last season we invested a lot of time and energy in developing a better understanding of our car. To this end, we focused primarily on the aerodynamic effects around the rear of the car. Our aero experts have done some great work in this respect, the basis of which has been used to develop the C32.”

Asked what the target was for 2013, Kaltenborn said: "The aim is very clear and simple: We want to continue to improve ourselves. The key factor for this is the car so the Sauber C32 is based on its predecessor which was a very competitive car. It had a lot of strengths and a few weaknesses and the engineers focused on building further on these strengths and eliminating the weaknesses. I'm confident that the entire team has done a very good job."

The car also has a new livery with grey becoming the predominant colour and white and red stripes retaining breaking up the livery on the monocoque. The C32 will make its track debut at Jerez in Spain next Tuesday, when the first of three pre-season tests gets underway ahead of the opening Grand Prix of 2013 in Australia next month.