you know, you Poms, all you have to do is pull the rear tub of your double cab utes & put a tray on
we can buy double cabs as a cab chassis, but some of the higher spec ones only come with the tub. Practically every double cab sold as a farm or tradies ute is a tray top. You wander round the back of any Toyota dealer & they've always got a heap of surplus tubs that have been replaced with aftermarket locally built trays
Bronco trays in Bathurst did mine and it’s great. Would definitely consider having one sent over