Fighting with a scavenger, Kendal receives a large bloody wound to her left forehead, yet when she flees into the desert to return home, the blood and wound have disappeared.
At the end when the airplane is started they show it being propped (started by turning the prop by hand) and the sound track is of the engine being started with an electric starter.
The distributor cap they were looking for was an automotive cap. Actual air craft have a magneto and wiring that is shielded and is connected with a threaded connector. Anyway the one shown in the movie would not fit a airplane magneto.
The multi-fuel M35 truck, from which Kendal stole the distributor cap, should not have had a distributor cap. It had no spark plugs and worked by injection of fuel into cylinders under high compression.
Desperately short of water, hiding from murderous scavengers and struggling to survive in a post-apocalyptic world, Kendal has clean shaven armpits, as are Grace's legs, a beauty routine no woman would (or likely could) continue in such conditions.
Twice Kendal is surprised and attacked by Carson's henchmen and both times she is lucky and kills them, but it doesn't occur to this intelligent and resourceful young woman to take their weapons for added protection and to stop Carson recovering them, even though she thinks it useful to retrieve her tomahawk and spent shotgun cartridges for reloading.
Kendal setting fire to her house at dusk and sitting nearby as it burns would reveal her location to Carson, the man she is trying to hide from.
In a post-apocalyptic world where everything is either gone or rare, Kendal simply throws her valuable lighter into the house to ignite the fire rather than simply lighting some form of fuse, as she has done previously.
It makes no sense that Kendal, a young woman in her late teens that was raised in an orphanage and has been living the last ten years in a post-apocalyptic world, would know how to fix or fly the plane that she found abandoned.
Hiding for years in a post-apocalyptic world with no source of electricity and relying on oil lamps and gas cookers, Kendal's electric radio still works, and is left on all night as if they have plenty of available power. Even if it were battery powered, they had no means of keeping the battery charged.