The Jaguar XK8 first came out in 1996 as a 1997 model. It had a 4.0 liter V-8 engine.
The 2003 XK8 was revised with around 900 changes/new parts including a 4.2 liter V-8, 6 speed ZF automatic transmission, and a lot of other stuff.
The 2005 XK8 was revised with a different exterior, larger exhaust pipes, and some other stuff.