At the fuel pump, they show Trevor's 4wd being filled with diesel, when the call-outs visible on the vehicle indicate it is a '3500 v6,' the petrol/gas engine.
Later in the film that same 'diesel' 4wd is put out of action when Ned puts petrol/gas in it.
When Ned is about to board his flight to Adelaide, the announcer calls for Flight QF793 to Adelaide. Flight 793 goes to Perth not Adelaide.