Jaguar has been seen testing their latest prototype, the 2008 XKR. The spy shots were captured during some cold weather testing. This convertible is lightly camouflaged indicating there may only be minor changes when the production model is revealed.

The spy photos expose some differences from the base model XK and the XKR. The XKR is definitely more muscular with its prominent spoiler, four exhaust tips, and hood bulge. The XKR should be sporting a supercharged 4.2-liter V8. This engine, while delivering a potent 400hp, will fall short of the competition. Mercedes, with their current supercharged and new normally aspirated 500+ horsepower V8s will top Jaguar's 400 horsepower XKR in pure performance. How these cars translate this big power and compete in the real world remains to be seen.

The XKR should be unveiled at the 2006 Paris auto show in October.