Mercedes offers Sneak shots of the F1 car the others have to beat in 2015

Mercedes did a shakedown test today at Silverstone, at times in hailstones and rain, of it's new 2015 challenger the W06.

Both drivers were in the UK today, with Rosberg on hand to drive the first few kilometres at a cold Silverstone, a few miles from the team's Bracklet headquarters.

The car completed a total of 18 laps (47.2 km).

The car is set for formal launch on Sunday in Jerez on the first day of F1 testing. Rosberg will test the car first.

The car has clearly evolved from the 2014 car, which won 16 of the 19 rounds, with a new nose in response to the changes in regulations for this year.

As the team has become more confident on cooling the hybrid turbo engine, it has tightened the bodywork around the side and rear of the car, as one would expect. Mercedes did extensive work on its rear end aerodynamics throughout 2014, to clawback the downforce lost with the change of regulations from 2013 to 2014, removing the lower beam wing and eliminating exhaust baling to the floor and this progress is sure to have continued for this year, although the sneak shots to not reveal anything of the rear.

It is known that within their 32 areas of permitted development, the Mercedes power unit has evolved in its packaging and plumbing, evolving a layout which had the edge over the rival engine makers last year. The mounting points will be the same however.

Some snatched video, issued by the team itself but made to look like a spy has taken them can be seen here on the team's Twitter feed. https://twitter.com/MercedesAMGF1

Here is a direct comparison of the 2015 (top) and 2014 (bottom) Mercedes cars.