As the subject implies, was poking around my engine compartment and noticed these protrusions of what appears the air intake.
What are their use, as there are three of them. My first thoughts are, this intake system can used on another Jag vehicle with a specific purpose?

 

Google ‘Helmholtz resonator‘.

 

Without having to google, they are acoustic dampers of a sort. They reduce the noise of the intake system.

 

What CJ said, some kind of resonator thingy

 

Will do. Never heard of it Thanks!

 

"Symphonator"?? I blocked mine off 'cuz I'm one of those weirdos that try to quiet my Jaguar as much as I can.

 

Nup, as kj07xk said they are Helmholtz resonators and nothing to do with the "symposer" which is on the other end of the engine (the back).

 

 

Again nup!
That is the "bark tube" which was used on the earlier XK X150 with the 4.2 V8, a different beast to the symposer on the 5.0 AJ133 which came in from 2009:
Although the OP has an '08 XKR which has the bark tube and not the symposer which has added to the confusion!