Port Augusta was (working) ATM free, and no real shopping centres for the size of the place get me out of here. (It turns out to be poor road signage, and that the town was on the Eastern side of the river/inlet. Port Augusta is industrial, and seems to specialize in power plants.
Arid zone starts not far north of Port Augusta. The land here is largely salt bush. There are some quite spectacular salt lakes near the road. The train line follows the road to west of Woomera.
Woomera museum opens M-F only. Park has rockets and planes (e.g. a Canberra bomber) and recovered rocket debris. Also the (now closed) detention centre is visible.
Leaving Woomera we enter the Woomera prohibited area, the impact on the driver is that there are no petrol stations for 250km.
Near Coober Pedy are the beginnings of the opal mines. These are distinguished by the truchs with large augers on the back, and the ground dotted with ~1m diameter holes and corresponding mound of dirt. Often there is an array of these holes in a small area.
Many residences in Coober Pedy are underground, like our motel and accompanying church. It is markedly cooler inside (a comfortable temperature year round). Often there is little above ground to indicate an underground house, just a 'shed' covering the front door and perhaps a carport. Look for air vent chimneys.