The Rain
The rain recurs throughout the novel and often acts as a transition. The image of rain in the desert and in the summer in general acts as a disruption from normal events, an anomaly. Ari, who himself feels like a disruptive anomaly most of the time, identifies heavily with it, saying that boys like him "belonged to the rain."
The Desert
El Paso as a setting for this novel is very important, and nowhere is more important than the desert surrounding them. The book often paints a picture of the desert, particularly at night, as a wide-open expanse where anything can happen, where secrets are shared, and where relationships are formed.
The Truck
The truck that Ari gets for his birthday appears frequently in the second half of the book. It represents independence for Ari, as it is the thing that allows him to begin to get around by himself. Like the desert, it serves as a setting for becoming, changes, and deep conversations throughout the novel. Finally, the image of the truck itself is a reminder of Ari's Mexican identity.
The (Lack of) Shoes
Ari and Dante are always running around barefoot; after the first time that the reader learns that Dante hates wearing shoes even when he is expected to, shoes and the lack of shoes show up everywhere. It always signals the characters looking for freedom from social norms.