Jaguar will unveil the XF-R at the Detroit Motor Show in January 2009 and sales will begin in 2010. Latest spy shots caught the BMW M5 rival testing in California.

Power comes from a 500bhp 5.0-liter supercharged V8, which will become the Jaguar family's shared supercharged engine. The blown engine should give the XF-R a 0-60mph sprint in less than five seconds and a top speed of 155mph. Like in the previous spy shots, the big visual difference between the the XF and the XF-R will be larger air intakes in the front bumper and the hood vents (same as the XKR).

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