I was there in Feb and my Mum used a fantastic company which fitted the (brand new) seat into her car for her. I think they have delivery and collection service too. They also have lots of other baby equipment for hire. I will find out what their name is and get back to you.
We are travelling with our 11mo DS to Sydney at Christmas and won't be hiring a car for the whole time. However, we will be using cars (inlaws, friends etc) whilst we there and thus need a car seat.
A few questions: 1. Does anyone know of a safe place to hire car seats from (if such a thing exists) in Sydney 2. If we bought him a car seat, could we use it in the UK? You can't use the UK ones there but are there restrictions the other way. 3. We're stopping in Singapore on the way there - what do you do about car seats there or do people not bother in taxis?