Our spies had to be quick, but they still managed to catch the Aston Rapide! These are the best pictures yet of the exciting four-door saloon that has the forthcoming Porsche Panamera firmly in its sights.

With stunning looks, V12 power and supercar performance it is set to be one of the most desirable saloons on the road.

As you can see, the Rapide is heavily influenced by the DB9 and DBS coupes. With the same aggressive nose, high waistline and low sweeping roofline it’s much more rakish than rivals such as the Maserati Quattroporte. However, a stretched wheelbase means that there will easily be room for four adults.

Clearly visible on this testing mule is the panoramic glass roof. Stretching from the top of the windscreen to the rear window it will help give the cabin a light an airy feel. The Rapide is likely to use the same dashboard as the DB9, while in the rear will be two individual chairs, making the Aston a strict four-seater.

Power will come from the firm’s powerful 6.0-litre V12, which should produce around 500bhp. As a result the saloon should sprint from standstill to 60mph in around five seconds and carry on to a top speed in excess of 180mph. There will be a choice of either manual or automatic gearboxes, both with six ratios.

No firm release date for the newcomer has yet been released, but expect to see the first cars hit showrooms late in 2009.