My five-year-old vehicle had a major mechanical failure on the 16th day past the expiry of the manufacturer's new car warranty. Is 'bad luck' a valid explanation by the manufacturer to avoid any obligation under Australian Consumer law?
Under the ACL, there are statutory guarantees that are separate and distinct from manufacturer/seller warranties. These guarantees are mandatory at law and are imposed on goods purchased after 2011. Given that your vehicle is 5 years old, it would not come under the ACL, rather, products purchased before January 2011 will be governed by the Trade Practices Act 1987 ("TPA"). There are similar statutory guarantees, known as implied warranties, under the TPA but they are less favourable to consumers.
One important difference is that under the ACL there is a "durability" guarantee. This is a new requirement that is not implied under the TPA. Whilst "bad luck" is never a good excuse, there is not much you can do to force the manufacturer/company to fix your car free of charge.