A dog that sits on the back (the tray) of a utility vehicle, and barks loudly at cars, children and other tray dogs.
Such dogs are usually associated with the so called Australian Bogan and tradesman (tradie).
These dogs are usually aggresive individuals of the blue heeler, kelpie or bull terrior variety.
The tray dog's back arched, owner nowhere to be seen and it's chain teather the only thing holding it back from mauling the weary shopkeeper.
2. Any one with an occupation such as a plumber or electrician, that has a ute with a tray dog or a white van with PVC tubes attached to the top.
The trady was doing well for himself with his plastering business, finally able to pay off the white trady van (complete with PVC tubes) and take his lovely wife Joyce and the kids out for tea at the pub.