Its very easy. Ive got VZ R8 interior in my VT. Just tap in to the cars wiring as the plugs wont fit (Negative and positive) And run a neg and pos cable from the passenger side seats to the drivers side and tap into them. I wouldn't cut the cars wiring as you can always take the seats out and rewire them if necessary (very very unlikley). Tuck the wire you ran from passenger to drivers side under the center console and no one would even know they were there. The airbag plugs plug up perfectly. Then get the airbag light cleared by a Holden dealer.
Let me know if you need anymore info. Heres a pic of mine:
View attachment 127060View attachment 127061
Shitty camera, pics dont do them justice.