I am looking to add bluetooth to the original alpine radio in my xk8. Ideas? What does the back of the radio have available as far as inputs? Anyone have a photo?

The stock radio has phone audio and mute signals located in the center console. This provides an easy interface for a simple Parrot or Motorola aftermarket telephone Bluetooth module. Search in the XK8/R section (this is the XJ section) for some write-ups on this.

If you also want to stream audio also over Bluetooth you need to add an auxiliary audio input adapter, because the radio does not come with one and this is a bit more difficult.