I have been looking for a forum for the AVIC and I think world wide your it!
I have just had installed an AVIC-HD3 which I think is a european version of your Z2 although our method of allowing the unit to work whilst driving is as simple as leaving the handbrake lead off which most installers here do
Aside from that things are much the same with the exception of the nav maps, mine is installed into a Monaro which you guys buy as a Pontiac GTO I believe
Anyway nice to have a forum like this