Almost certainly not. Unless there’s some strange quirk of manufacturing that allows the mounting points to magically line up, the current Isuzu D-Max is an all-new design, compared even to the most recent predecessor, let alone the model from 2006. The 2006 D-Max shared a lot of its architecture and engineering with the Holden Rodeo and later Colorado, while the new D-Max is a joint venture with Mazda and forms the basis of that company’s BT-50 range of utes. You may be able to engineer a set of adaptors to mount the early nudge-bar to the later vehicle, but at some point it’ll get messy and simply not worth the time and money investment compared with buying a nudge-bar designed specifically for a 2021 D-Max. There’s also the issue of whether the old nudge-bar design would be compatible with the air-bag system of the new Isuzu. Again, almost certainly not is the short answer.