I'll be there in Mar 25, if you could give update in Feb please, though will probably hire a car (yet to check the airport surcharge)I was looking up how to use Public Transport from CHC, seems you need a Metrocard or cash. And Metrocards are not sold at the airport or available to pre-purchase and delivery outside NZ. But it lead me down the hole of finding out about the combined travel system - called Motu. Here's the update from June:
I'll be in CHC in Jan and Feb 2025, so if I'm lucky this may have been implemented by then.