Quick-- its a 12/01 Build.

Several options:

1) Get a phatbox. Works with any X5. Check out Phatnoise.com. You do however lose the ability to have the CD Changer if you have one. Its either PB or CD changer, but not both.

2) If you do have navigation, which I suspect you don't, but if you do, you can try TV on NAV's video adapter with stereo inputs. Then you can use a n IPOD or whatever you want to port sound in.

3) Also, soundgate and blitzsafe each make an adapter to add external audio through the CD Changer interface. CD player not required. In fact, the Blitzsafe adapter replaces the CD Changer when adding a PhatBox(comes with the PB). I have 2 PhatBoxes and they rock!

So, you do have options. Phatbox is the most expensive, but if you don't have a CD Changer, its a good way to go.......