Of course, same. I've got VZ Vents in my doors. You ask Holden people at their spare parts area and they will say no their different. Sure they might be as in colour but Holden did not change a thing. Same bolts clips etc.
Back to the VY dash conversion. It might sound a synch base to base. But try it moving up the model line. This i heard took one guy many weeks and twice the amount or wires over the VT-VX.
If you are talking about a Calais, Clubsport etc... with say climate control, traction etc, same deal.
Everthing can be swapped with ease. Both the traction harness and the climate control wiring harness are the same. You still need to remove plug and colour match the wires as Holden changed each pin on all harnesses.
As stated I have read so much on converting the interior of a VT to VY.
Alot of people just assume things and do not know what they are talking about.
Just thought to advise the simplicity if indeed interested in doing the job.
Moving up the model line can be difficult for some, if you can join a wire and you have the correct parts to install the interior, I do not see it taking more than a day or 2.