At the end of the movie, when the Mayor gives Arthur instructions how to drive and smash the punk's car, his fake beard changes places between shots (under his chin - on his right cheek).
At the end of the movie (when the people leave the village) you can see a green Austin A30 Van. The same car is crashed earlier by a car trying to jump over the Austin using a ramp. The whole front is crushed so there is no way it can be repaired.
When George pays for his petrol he uses paper money that is obviously not Australian.
A watchman enters a warehouse with a watchdog and he finds Charlie hiding behind a hooded car. The watchdog barks as they enter, but there's nothing to be heard.
The people thrown from the car in the first accident are obvious dummies.