Your budget limits you to older models, such as 2008/2009, which will have done 120,000 to 180,000 km. I am loath to recommend buying one of these cars with such a mileage on them; you would be heading the period of pain when you are quite likely to face increasing and expensive repairs. If you were to choose to buy one I would go for the Discovery. I would also urge you to have the car you choose checked over by a specialist mechanic who knows the brand intimately. Instead of the European models you are considering I would suggest you also look at something like the Toyota Kluger, which would likely to be more reliable and less expensive going forward, and your budget would stretch to a later model.

We don't have lemon laws like they do in the United States, which is unfortunate, because you seem to have copped a lemon for sure, and under the US laws your car would almost certainly be replaced. You are right in demanding it be fixed, and also right in telling Audi not to return the car until it is fixed, but I would have gone further and demanded they either replace an apparently faulty car or give you your money back. I would suggest three things you could do to achieve a resolution to your problem; first contact Audi head office in Sydney and demand to speak to the Managing Director, second contact the consumer affairs people and enlist their help, and third consult a lawyer with a view to sending Audi a letter demanding action.

Under the Australian Consumer Law introduced in January 2011, a consumer can request a refund or a replacement for persistent problems if the car doesn’t do the job it’s supposed to do.