In fact I have noticed a number of these sonic screw drivers popping up all over the place. There may even be one near where you live 
I believe there is a conspiracy.
A certain Doctor has been secretly placing sonic screwdrivers all over Australia to repel the Dalek invasion that will soon take place. I hope it works.
When approaching GZ be aware that there may be muggles. It is best not to stop on the Gawler By Pass - There is another way.