Although Williams haven't confirmed when or if they will be officially launching the 2011 car, we got our first look at the FW33 today in Valencia.

Running with the traditional testing colours, in a delicious dark blue, the car showed off a higher nose, and some redesigned sidepods, plus some high-profile PDVSA sponsorship.

Sam Michael, technical director of Williams, is confident the design they are going for is a good base to start from to help improve on their sixth place finish in the championship in 2010.

The design of this year's car has been pretty smooth We've improved our way of working by increasing the communication between the mechanical and aerodynamic departments, and that improved our decision making processes. It allowed us to increase the optimisation time spent on each part of the car.

- Sam Michael

One part of the car that has either seen a lot of work, or not enough, is the rear end. Spotted during testing today, the Williams is sporting an unusual rear end that has a lot of air space and little carbon fibre. Described as 'extreme' the lower rear end could bring the team significant performance gains.

We already know that Williams have changed their mind on the version of KERS they will run, having spent a lot of time and money investing in a flywheel design. For 2011, they've switched to the battery version of the device that the rest of the field will run as well.

The car will feature some aerodynamic upgrades before the season begins, so any testing times won't be reflective of the pace of the car. Barrichello is behind the wheel today, with Maldonado taking over duties towards the end of the week.