The girl at the high school gymnasium who speaks into the microphone questioning the existence of God in light of Wayfarer 515 is played by Taylor Dearden, Bryan Cranston's real-life daughter, and the woman interviewed on television about the crash, Robin Dearden, is her mother and Cranston's wife.
The figure that the twins crawl on their bellies to pay homage to (along with everyone else) is Nuestra Señora de la Santa Muerte (Our Lady of the Holy Death). Often shortened to Santa Muerte, she is a female deity and folk saint in Mexican neo-paganism and folk Catholicism. However, she is always depicted as a skeleton; she was never a living human like traditional Catholic saints.
Luis Moncada has tattoos on his eyelids that read "Fuck" and "You." They had to be carefully covered with makeup. When Bryan Cranston asked if his eyelid tattoos hurt, Moncada stated that the needle did not hurt but the metal spoon that they had to place over his eyeballs did.
The boots worn by the cousins (Leonel and Marco Salamanca) are tipped with silver skulls in the opening scene. The same silver skull can be seen in the key chain of Jesse Pinkman in Seven Thirty-Seven (2009).
In the scene where the cousins blow up the truck, the footage of the explosion was filmed from far away using a long-focus lens. This had the effect of shallowing the perspective and making the explosion appear much closer to the actors than it really was.