In the "Inauguration" scene, the cutout of Hitler is seen alternately standing beside a loudspeaker and then a cutout of Nixon, and back to the speaker.
The Toyota truck is ruined after going off the road into the ditch, or at least immobilised. Nevertheless, it is pristine in the following scene.
The crew was very careful during takes to not to film any activity in the background of scenes that would spoil the illusion of there being nothing living left on Earth. So much so that the assistant director would constantly stare at the background where ever the lens was pointing during takes to ensure nothing was inadvertently caught. However, as mentioned, a car can be seen in the far distance in the scene just before Zac goes into the church and again at about 1hr 3m 03sec when Api and Joanne are jogging down a foggy hill, a white car can clearly be seen driving past in the top right of the frame.
When Zac is driving the big earth-moving machine (at around 33 mins), just as he stops, through the window of the truck in the upper left of the screen a car passing in the distance can be seen.
In the scene where Zac cries "aaa!" in the cathedral, a white car passing in the distance can be seen.
When Zac is driving around the garbage truck at the beginning, a bird can be seen landing on a telephone wire in the background.
Zak and Joanne each have one of two radios for communicating when they're apart, but when Zak meets Api and then returns to find Joanne, he and Api now have both radios.
Signs of people that have disappeared are everywhere in the beginning of the movie. But it seems that they took their clothes with them, but left cars and other things that surrounded them. The exception are babies, who left even their blankets and supposedly left naked.