I think you must have an international driving license. Go to transport department to apply for it. You can have it immediately. It cost you about $80.
國際駕駛執照 is only a translation of the driving license that you hold. Don't believe that you need a 國際駕駛執照 just because you are driving out of HK.
I rented from Hertz in Brisbane back in April, I showed my UK driving license (no passport is needed), paid with my HK credit card, and my wife (who didn't even have to show her driving license) was entitled to drive (no extra insurance payment is needed).
國際駕駛執照 is only a translation of the driving license that you hold. Don't believe that you need a 國際駕駛執照 just because you are driving out of HK.
I rented from Hertz in Brisbane back in April, I showed my UK driving license (no passport is needed), paid with my HK credit card, and my wife (who didn't even have to show her driving license) was entitled to drive (no extra insurance payment is needed).
Some states will allow you to drive for up to 3 months using your foreign drivers license, while others will require an international licence. You should check with the relevant state authority using the links below.
I have also checked my HK driver license and it is in both Chinese and English.
If you are still worried, best for you to check with the car rental company and find out if they will need to see your IDP when you pick up the car. HKD80 is very little money considering how much you will spend in Australia, it's the hassle of going to Dept of Transport, filling in the form, queuing, waiting...