WARNING: This page is about a different car, the 2011 Jaguar XKR, 2011 Jaguar XK, 2010 Jaguar XKR, and 2010 Jaguar XK. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of JAGUAR CARS, INC.
The RFI (radio frequency interference) suppressor is installed on the engine harness carrier at the rear of the engine.