Along with such pests as jackrabbits and kangaroos, Australia  »a few years from now » is being afflicted by predatory motorcycle gangs. An elite leather-clad highway police force has been established to oppose them. This is the flimsy plot line of  »Mad Max, » which opens today at the Embassy 5, but it provides an adequate framework for some vivid chase-and-crash sequences across the unpopulated outback and a heavy dose of sadism with obvious homosexual overtones (…).  »Mad Max » is ugly and incoherent, and aimed, probably accurately, at the most uncritical of moviegoers. — Tom Buckley, 1980.