Eugene and Velma enjoying the Barrow gang (Situational Irony)
When he first gets in the car to pursue the Barrow gang, Eugene is very angry about the fact that they stole his car, and he wants to catch up with them to confront them about it. Then, he and Velma end up getting in the car with the Barrow gang, who heckle and hassle them for a while. As they continue on their journey with the gang, however, Eugene and Velma become more charmed by the criminal gang and start to get folded into their social fabric. There is irony to the fact that the bumbling square, Eugene, who can barely contain his rage at having his car stolen, ends up eating hamburgers in the backseat of his own stolen car, before getting unceremoniously dumped on the side of the road.
Bonnie's poem gets published (Situational Irony)
By the end of the film, Bonnie and Clyde are the most wanted criminals in Texas. They are hiding from the law at C.W. Moss's father's house and keeping a low profile, as revealing their whereabouts would expose them to almost certain death. In the midst of this high stakes situation, Bonnie writes a self-aware poem about their experiences as criminals and sends it to the paper, which publishes it. It is ironic that in the most high-stakes moment of the film, when death is almost inevitable, not only does Bonnie submit a poem about herself to the newspaper, but the newspaper opts to publish it.
Hammer figuring out Moss' name (Dramatic Irony)
Hammer exploits Blanche's blindness at the end of the film by going to her room and performing his sympathies for her problems. In the midst of asking her about her hardships, he manages to get her to tell him C.W. Moss' name, which has been previously unknown to the authorities. While the viewer knows that Hammer is just using her to get information, Blanche thinks she has finally found a sympathetic ear, and she cannot even see when Hammer leaves the room before she's done talking. This is an instance of dramatic irony.
Bonnie and Clyde's death (Dramatic Irony)
At the end of the film, the viewer knows that Moss' father and Moss have cooperated with the police in order to lead them to Bonnie and Clyde. Bonnie and Clyde have no knowledge that the police plan to kill them, and so are blissfully unaware as they drive back to Moss' father's house from town. The disconnect between Bonnie and Clyde's naivety and our knowledge as viewers accounts for a heightened dramatic irony at the very end of the film.
