New Audi A8 spied

These are the clearest pictures so far of the new Audi A8, which is set to be unveiled later this year.

The new A8 has been spied testing around the Nurburgring in heavy disguise previously, but has now begun its final phase of development in lighter camouflage.

The Mercedes S-class, Lexus LS and BMW 7-series rival will use a weight-saving aluminium spaceframe and be around 10cm longer than the current model.

It is also expected to get a cleaner and more efficient range of engines, including 3.0-litre and 4.2-litre V8s. Front and four-wheel-drive versions are likely to be offered for sale.

Audi says the car will be unveiled in late autumn, and it is expected to go on sale in the UK in early 2010.