IMHO, don't do Alice to Darwin at night - there are too many interesting things to see along the way, including Tennant Creek Telegraph station, a few abandoned airfields, hospitals etc, Katherine Gorge, Mataranka springs etc.
Adelaide - Alice is a bit more boring, but Woomera and Coober Pedy are must-sees (it's all relative of course, but if you're travelling, I'm assuming you want to see things!)
Adelaide - Perth has some long boring stretches, but check out the old Eucla(?) telegraph station and also the coast along the G.A.Bight when the road gets close.
Attempting to do these long stretches at night is selling them short, I think, aside from the obvious dangers.