I don't know what you mean by "aux cord", there is a standard iPod/iPhone 30 pin dock connector and when connected to it I can change songs with my steering wheel controls, or use the nav screen to pause, skip ahead etc.

 

Does it work with an iPhone 5?

 

Hi, I'm also buying an '04 XJ8. Very interested to learn of your experience with ACM to see if it works to your expectations. I'll be grateful if you can let me know once you have yours installed.

 

Somebody else on another thread said that if you get the adapter cable, it works fine with iPhone 5. Good luck.