Another word of advice that I use EVERY time I buy a car.
Before I leave the lot I call NRMA / Justcar insurance and say "I want to insure this car, here are all my details, and please send me the bill for the costs". Even if you have NO intention of using that insurance company they have now covered you.
The cover starts as soon as they give you a policy number and they are legally obliged to pay out in the event of any claim even if you haven't paid the premium yet. This gives you around 2 weeks to "shop around" for insurance but you are still covered for anything in the mean time.
Last time I bought a mazda run around car I rang up NRMA said, please insure me, here are my details. They said "sure that'll be $500". I said ok fine please send me the bill, they did so. 2 days later i took out a policy with AAMI for $300 and paid them instead. NRMA covered me for the 2 days it took me to shop around for AAMI.
They are very careful to tell you that the policy begins immediately and they even give you a policy number on the spot. Write it down.