Audio Visual Dvd Confusion

[pauldo]

New X5 owner, not very much a car person in general so bought it because I like the look of it (this hopefully doesnt exlude me for help- I do intend to get to know it and appreciate it)

I have a screen up front, and 1 in each headrest.

in the boot, I have a PS2 which when switched on will display on rear screens (not front screen). - However, there is no sound. There are 2 sets of headphones, but neither work, so no volume when watching images from PS2 in rear.

There is a DVD player in boot but contains sat-nav Dvd so recckon I cant watch DVD on this because when I put Shrek on it didnt appear on front or rear screens.

I aint got a scooby doo what to do, any ideas would be hugely appreciated- even a recommendation for a Scottish based expert who will not bend me over.

Thanks