View more pictures of the Cadillac CTS-V

The unofficial lap time for a Dodge SRT-10 ‘Viper’ supercar is 7:59, while the 500bhp BMW M5 super-saloon has been unofficially timed at 8:13.

The famous German track, nicknamed the ‘Green Hell’ is a torturous 13 miles of undulations and challenging corners – perfect for testing cars to the limits of their ability before they go on sale.

Cadillac has racked up numerous laps finalising development of its 6.2-litre supercharged V8-engined CTS-V with 550bhp.

Its suspension reacts to driving conditions thanks to magnetic fluid inside its dampers which can change suspension characteristics in an instant.

The American carmaker is offering a manual six-speed gearbox for the first time to suit driving purists, while a six-speed automatic is also available with steering wheel-mounted shift buttons.

Cadillac began its UK comeback in 2005 with the first generation CTS saloon. The hottest version was fitted with a 5.7-litre V8 with 400bhp – 150bhp less than the new flagship model.

Production of the latest CTS-V is due to start in Autumn and we hope to see it in the UK in 2009 for less than £50k.

View more pictures of the Cadillac CTS-V