Cable

 

Does it fit in the OBDII port connector that's located under the left side of your dashboard, above the driver's left leg? If so, it looks like it's an extension that goes to an aftermarket accessory of some sort, probably a code reader. Just my guess.

 

Looks like the iPod adapter

 

Definitely not an old adaptor, my car by is an 07 does it have an iPod

 

iPod connectivity integrated with the touchscreen and steering wheel controls became standard equipment on the X150 beginning with the 2009 model year - the last of the 4.2 cars. A dealer-installed accessory Audio Connectivity Module was available to retrofit similar capabilities to 2007 and 2008 models. For details, see: https://www.jaguarforums.com/forum/x...-module-85285/

 

iPod Classic 30 pin adapter cable!