Well, not quite certain how similar things are in Oz, but my suggestions are:

1. Go with a smaller lender (e.g., a credit union) over a large bank -- they tend to offer better rates.

2. Secure financing BEFORE you go.

3. Do NOT let the dealership know how much financing you have -- just tell them you have it and strike the best deal you can.

4. Do NOT take the first offer they throw at you -- I've stormed out of dealerships angrily, and guess what, they generally call back tomorrow with a counter offer (maybe this is a USA thing :p )

5. Do not bother getting any extra bells and whistles the dealer offers (e.g., undercarriage coating, etc.) it's never worth it. Even extended warranties aren't worth it -- they can be gotten at a later time, and unless you plan on keeping the car for longer than 6 years, why bother?

6. The dealer may offer to get you a better rate -- that's dubious and allowing them to check will ding your credit -- just stick with what you have, it's probably about as good as its going to get.

Check this crowd out...

Best Car Finance & Car Loans - Instant Online Quote - Car Finance Broker Australia - Stratton Finance

When I was hunting around they had the most competitive rates. Plus they also offer all forms of finance - Loans, leases, consumer hire purchase, etc.

They can advise you on not only what suits your financial situation but also what will gain you the best tax advantage.

Hope this helps.

My mate Adam does all finance and salary packaging at Salpac. You'll be able to pay for the car with pre-tax dollars if you set it up correctly. It'll save you a tonne of cash in the long run.

Ask him to explain the different types of finance like Commercial Hire Purchase, Chattel, Spouse, Associated, Novated, and he'll suggest whats best for you. Say you know Darren though the 370 forums.

Salpac - Salary Packaging and Salary Sacrificing Specialists

Small banks can give a better option...or if your military use USAA...4.25% depending on your credit. >_<

deposit also can help ... would rec a min 20k if you can