"Thank you for taking the time to contact Subaru of America, Inc.
We are the distributor of new Subaru products for the United States only. We do not have information on Subaru models offered in other countries. We also do not have information on other countries' government regulations. The 2012 Impreza offered in Australia may have the same design as those offered in the US. It may be that the Australia government regulations are different for trailer towing than our government.
As you are aware, Subaru of America does not offer a trailer hitch for our 2012 Impreza models nor do we recommend having an aftermarket hitch installed. If you do decide to equip your 2012 Impreza with an aftermarket trailer hitch, the warranties on your vehicle would not be voided. However, if an issue arises because of an aftermarket product, the warranties may not cover the repairs.
Thank you, Alan, for the opportunity to be of service. Happy 4th of July!"