Car Magazine caught the upcoming Cadillac CTS-V testing fully undisguised. The American response for the BMW M5 will be unveiled in January at the Detroit Auto Show.

The all-wheel-drive CTS-V will be powered by the mighty 7.0-litre all-alloy LS7 powerplant borrowed from the brilliant Corvette Z06. It will have a maximum output of 512bhp at 6300rpm and a peak torque of 470lbs-ft at 4800rpm.

Cadillac announced a top speed of 175 mph and the 0 to 60 mph sprint in just 5 seconds.

On the UK market the CTS-V will be priced at £45,000.