Ben-Hur

When Walter battles the Germans at the end of the film, we see a sign for Ben Hur Auto Repair. This is a reference to Judah Ben-Hur, the fictional hero of the 19th century novel by Lew Wallace, Ben-Hur: A Tale of the Christ. In the novel, Ben-Hur is a Palestinian Jew who single-handedly battles the Roman Empire in an attempt to free his enslaved people. The story was so popular that they even made a blockbuster movie out of it starring Charlton Heston.

The character of Ben-Hur is significant for Walter not only because Walter is Jewish but because he represents how Walter sees himself in the world: a single warrior defending an unpopular cause. Walter brings this attitude to the table regardless of whether he's engaging in combat in the jungles of Vietnam or bowling. His "us vs. them" mentality influences his attempts to help The Dude: he fights against the perceived enemy with gusto, often steamrolling The Dude's attempts to keep things peaceful. His friends are a tribe, just like Ben-Hur's, that need to be protected.