Mad Max and The Road Warrior are two of my favorite movies. Beyond Thunderdome is nowhere near as good, though it was made (largely) by the same group of key talent. When watching the trilogy films back to back, it's easy to see what happened with Thunderdome -- they threw money at it. There are some great ideas there, but the money added up to expensive, outlandish costumes instead of scrappy ones, architecture that would be a fortune today (much less in the de-industrialized future) and extraneous crowd scenes. It all adds up to a lack of believability and the deep but straightforward characterization that the first two films have, which makes it that much easier to invest in their plots. You have to believe in the world and care about the people who inhabit it in order to give a flying fig about any death or car chase or fight happening on screen.