May have been racing the Camaro in a late-season meeting in Australia, and sent the Nova on by boat to make the race deadline easily.
But what's much more likely is that his appearance at the previous December '67 meeting in the Nova in its' black Neptune livery introduced the crowd to the spectacle of not just a tough race driver in action, but the emergence of an actual motorsport showman, with a larger-than-life persona, an energetic, happy, positive bloke who drove with glee, sliding and wrestling the previously-unseen Nova to victory at their first attempt at an International event in Bay Park's inaugural year. I would think when the time came to get Stormin' Norm Beechey back again, the Nova would have been the first-requested accessory !