Jaguar has just put into production the XF unveiled at the Frankfurt Motor Show and a R version of it has already been caught testing. The XF-R will be powered by the same supercharged 4.2-liter V8 from the XF, but tuned to a higher state of athleticism. Output will be closer to 500 hp.

The Jaguar XF-R features sports quad pipes at the rear; the ride height is noticeably lower; the mesh grille is menacingly blackened.

The R version will b unveiled at a motor show in late 2008, with sales kicking off in early '09. It should be one of the fastest four-doors on sale, with pace to challenge the Mercedes E63, Audi RS6 and BMW M5.