I have a 02 x-type sport in need of a piece on the rear bumper. Its the plastic piece that all the reverse sensors go into and clips into the bottom of the bumper just above the exhaust pipes. Anyone have any idea what this is called or where to buy one? I dont need the reverse sensors, just the bumper insert that they all fit into.

 

Might be called a rear bumper skirt.

Call a dealer to get the Jaguar specific terminology. They have funny names for stuff sometimes.

 

Working in a bodyshop parts dept some manufacturers call them spoilers (yes even though they are at the bottom they are on invoices especially from VW as spoiler) or a rear valence.
I would call it a rear valence to avoid confusion