Cars is anything but family-friendly. Cars is terrifying.
To the untrained eye, Cars may seem to be a wily tale of a couple talking Cars who have all the same problems as humans. This is just an illusion, however. This is an act, cloaking the true message of Cars.
When closely observing this film, we realise one omphalic fact. We start to understand the significance of the movie's setting. These Cars are clearly roaming free in America. The dialogue discernibly mentions California. Route 66, the Golden Gate Bridge, all of the intricate and even recognizable cities and towns are clear indicators of a human presence. Unless someone really wants to argue that these cars built all of this? ...I didn't think so.
Cars is sonorously set in man-(or woman)made America! (You're welcome, Caleb)
That being said, where are all the humans? Why are these fictitious representations of vehicles the only animate lifeforms we witness during this hour and a half movie? I see only one possible answer: Somehow these abominable automobiles gained animated mortality, and then proceeded to either destroy, or inconspicuously enslave all of mankind (yes Caleb, and womankind).
Why would Pixar choose to take on such a dark tone with this particular venture into animated cinema? I do not know. Maybe Pixar is telling us something. Maybe they're warning us of something......?