What about rust? I hear it is an issue on UK imports.

Corrosion, or rust is something you need to be aware of on UK imports.   Salt is used on the roads in Winter.   And just because the vehicle passes an MOT (like our WOF) in the UK, does not mean it will pass our compliance checks on entry in NZ.   NZ compliance inspectors are very strict re corrosion.   And if found, it will need to be repaired before the vehicle can be passed.  The costs to do this will of course depend on the work required and it is likely a repair certificate or LT400 will also be needed.   These are issued by specialist engineers, and will involve additional costs as well as time.     Most of the vehicles we import are new or near-new so this is not an issue, but with older vehicles it is something you should be aware of.