Hello people,
Well happy to have found this place. Recently purchased an AVIC-HD3-BT unit from another forum member (I am a moderator on a UK based BMW forum) and have done the majority of the hardwork modifying the heater box etc to create clearance for the unit. Purchased a bezel from mybimmer.net which i can highly recommend - quality is fantastic and looks very OEM. 
Right, i'm off to go do some searching cos i've got a few issues i need to find answers to and i'm sure i'l find plenty of stuff new stuff on here to make it even better!
Marty