The worlds of Mad Max and Death Race 2000 present us two separate versions of a dystopic continent after *something* bad happened in 1979.
In Mad Max, we are only ever shown the Australian continent and the aftermath of an oil shortage and ecocide. The 1979 oil crisis got worse and the Iranian Revolution spilled over into surrounding countries until the world was at war over resources. The Australia of Mad Max eventually fell to the state it's in when authorities are unable to protect its own citizens anymore and the titular Max becomes a sort-of lawbringer to the Outback.
In Death Race 2000, we are only ever shown the North American continent and the aftermath of something referred to only as the "World Crash of 1979". In the universe of Death Race, every year as a form of circus and peanuts, Mr. President hosts a cross-continental race where violence isn't just encouraged, you get points and perks for killing specific types of people...like younger and more virile people being worth way more points.
Now, here's where my theory comes in. I think that the world events of 1979 are the same in both versions of the movie, just told through different propaganda lenses. We are in the year 2000 when we first enter the world of Death Race 2000 (obviously), so some time has passed and a lot of people have died out. The ones who remain are not just a bit fanatical about Mr. President, they are completely devoted to him because he *rewards* them with the Death Race every year. They'll believe anything they are told.
What do we know about the World Crash of 1979 in Death Race? Well, we know that people of color are a thing of the past in America. There isn't a single person of color in the entire film. In fact, Nazis are not just acceptable now, they are a fan favorite in the race.
We know that the president only appears in person once a year, to shake the hand of the Death Race winner, and is probably hiding out because he's cultivated a country that is obsessed with death and dying. What's to stop someone from killing him?
We know that America as a whole is **incredibly** isolated after whatever happened in 1979 and we don't hear about anything outside of the North American continent happening.
My theory is this. The "World Crash of 79" *was* the more dangerous and serious version of the oil crisis and Iranian Revolution from Mad Max. Australia, given its already pretty isolated state, was quick to fall into chaos and turned violent fast before rebuilding into the version of Australia we see in later films. North America, too, became isolated after the world ended and, like most times in history when this happens, blamed minorities and outsiders, became a fascist dictatorship, began distracting its populace with sport and spectacle, and now sits alone and comfortable in its own bubble.
They are the same universe. Happening at the same time almost. Roughly around the year 2000, roughly 21 years after the real world Iranian Revolution began and (in this new joint world I've theorieized) turned way worse and very violent.
To make it even more fun, the worlds of both universes pride themselves on their unique cars and obsession with death.
So what do you think? I googled it and no one else has made this connection I think. I mean, it's not at all possible of being a real thing, these movies were made 4-5 years apart, oceans from each other. I sincerely doubt they actually wrote them this way, but the fact they were both playing with the same ideas seems to suggest a sort of... spiritual connection.