Can I replace the head unit in my X350 (2004 XJR) with something a bit more modern? My head unit also controls the AC, but there are separate buttons for my AC. I'm curious if they will continue to work without the factory head unit.

 

I did a total replacement of my head unit in my 2008 XJ8L (358), but it had the head unit separate from the climate controls. I'm a bit confused by the way you describe your controls. If you have the nav screen, what I did will probably not work for you. As the 2008 and later got into fiber optics to the amps/speakers, I had to replace everything. You should be able to use much of what is there. I went with a Pioneer unit with dvd/cd/nav/sirius/bluetooth/backup camera. I will provide pics shortly. Good luck!

 

Here are pics of my project in my 2008 (358).

 

Nice job. Your before pic on the left looks nothing like mine. I have the touchscreen setup with Nav, CD player, radio etc. It also has screens to control AC. I am told by some of the shops around town that if I had to replace the until, I may not be able to control AC and other functions.

 

With the nav unit you are out of luck, unless you are willing to strip everything and go back to the base unit like the picture above.

The nav unit controls the screen, climate and the audio HU. The audio HU controls the radio, cd, cd-changer, amp, phone and voice recognition - via the most obscure system ever invented.

Another complication with the nav setup is that you have "premium sound" which means your speakers are wired to an amp in the trunk, so you either have to put a separate amp in the trunk or bring the wires to the new HU in the front (not impossible, but annoying).

 

Can you share some more information on your install please. Where did you find the mounting kit?