Four things. First, check the Personal Property Securities Register (PPSR) for money owing on the car: if there is a loan against it, the lender can repossess it from you. Second, insist on a Warrant of Fitness (WOF) less than one month old for a light vehicle. Third, check the registration (rego) is current; if it has expired you pay the fees from the day you buy. Fourth, confirm the seller is the registered person, then both of you notify NZTA of the change of ownership straight away. Buying from a licensed dealer gives you Consumer Guarantees Act protection; buying privately does not. Source: NZ Transport Agency — https://www.nzta.govt.nz/vehicles/buying-and-selling-a-vehicle/buying-a-vehicle and the PPSR — https://ppsr.companiesoffice.govt.nz/