They may be thinking of another movie in relation to the climate change part. I have heard several people the past couple of years (who have clearly never seen the movies) talk about how the “oceans have dried up” in Mad Max, which is clearly NOT the case.

To be fair though, the world has gone under massive ecocide in Fury Road, but that isn’t climate change so much as climate destruction.

And on the car bit, I couldn’t agree more. Not only are they using the cars for actual survival, but the amount of people who actually have functioning cars is miniscule. The entire plot of mad max is war over resource shortage which includes oil. In thunderdome they were literally making fuel from FECES. In 2, Max tried extracting fuel from a gyrocopter lol.