New car registrations rose by more than a third in June, to just over 5700 compared with last year.
Used car registrations, which are generally imported used cars, totalled 7400 last month - just 0.3% more than in May.
New commercial vehicle registrations rose by nearly a quarter to 2200 compared with the previous year.
Motor Trade Association chief executive Perry Kerr says he's hopeful sales have turned the corner on 2009.
Paul Bond of dealership Stevens Motors in Lower Hutt says the rise is due to an improvement in the economy, a positive outlook from consumers and some stock arrivals.