On that same trip though the Simpson Desert we were quite lucky with the wildflowers. Apparently there had been some rain lately and the red sand dunes were covered with wildflowers.
This photo was taken along the WAA-line and shows a field of Annual Yellowtops. Although by no means very special or scarce, their sheer numbers make them very pretty and their yellow colours go very well with the red sand and blue sky.

(Please, click here or on the photo to see more photos of this location)
The good thing about going so slow is that you have ample time to enjoy the wildflower!