Well I would really like to take out the standard DIN Jag head unit and replace it with the empeg - it'll look better than having to make something up for the extender.

The problem is that when you remove the head unit the satnav doesn't work. Rumour suggests that the satnav notices the head unit security state (ie missing or 'code' not entered).

So I need to bypass the satnav security - quite specific to Jaguar (and Google suggests maybe Volvo) I guess.