For the scene in which Skyler (Anna Gunn) visits the Four Corners monument, Anna Gunn wasn't actually there. The upward shots of Anna Gunn were filmed in the studio parking lot, and the scenes of Skyler at the monument in the car and flipping the coin were of another actress.
The opening scene includes an accurate portrayal of carbon monoxide poisoning. The cherry red faces of the guards is typical in carbon monoxide poisoning.
The appearance of Walt Jr.'s new Dodge Challenger was the result of a product placement deal with Dodge.
This is the episode that includes Walt's infamous "I am the one who knocks" speech.