They did the GTO, G8, Caprice, and SS, but I think I read that it's pretty expensive for GM to build them in Australia and bring them here. The
Chicken Tax (25% tariff on imported light trucks and other goods) is probably why they never imported any Utes. They would've had to build them here to make it feasible. There's also the Ford Falcon Ute sold in Australia. I bet the profit margins wouldn't be as high as the regular trucks they would steal sales from and that's why we don't get them.