After a night of hearing his parents fight about the possibility of another mouth to feed, Gus a ten-year old boy, decides to cash out his piggy bank and take off in a stolen Ford Mustang. His plan is to collect all the MOTORAMA cards across the country, and claim the grand prize, which will set him up for a promising future. The cards are only available at specific, participating gas stations.
Most characters who Gus encounters strangely seem to treat him like an adult. At a gas station, he indirectly causes an attendant, Phil, to be hit by a truck. Staying the night at a motel, he encounters the owner, who kills any squirrels he catches with exhaust fumes.
Leaving the next day and running low on money, Gus decides to steal some gas. However, the owners of the vehicle catch and knock him out, damaging his eye socket. The couple brings him to their place, realize he is a kid, and call a doctor. But instead of allowing surgical repair of the eye, they decline an operation. In a surreal sequence, the couple smears makeup on themselves and Gus, and it is implied that the couple molest him. The next morning, Gus dresses and leaves, only to find a decrepit Motorama Billboard, making him question his whole journey.
In low spirits and with no apparent way of finding more money or gas, he stops for food. Now wearing an eye patch over his lost eye, a biker identifies him as a pirate and challenges him to arm wrestle for money. Gus loses. After a dispute of cheating and revelations about his quest, the bikers humiliate him by branding him with a demeaning tattoo.
Stopped at a rest stop, still desperate for money, he gambles with a father over a game of horseshoes and wins. The father then decides to take this as a chance to abandon his children, and he and his wife take off.
His journey nears completion with just one letter remaining. Gus drives onward, through a dark and menacing industrial park called Essex, where people fight, burn crosses, and take drugs. On an empty, rain soaked highway he swerves to avoid a truck and drives his car off an unfinished bridge, damaging it so he can no longer drive.
Walking back along the road he encounters an older version of himself, driven crazy by the fact that he never found one last letter, the same one Gus is missing. Gus comes across a mentally handicapped gas station attendee and buys gas, only to receive just one card in return. Fortunately, it turns out to be the final letter he needs. His hair now gray, and viewed by everyone in the world as an old man, he heads off to the company offices to claim his prize.
At the company headquarters, a representative explains over the phone in the lobby that collecting all the letters does not make Gus a prize winner; he is just 'eligible' for the prize. Not giving up, he heads upstairs and tries to meet with the company executives, but only gets as far as the secretary. Everyone now sees him as the small child he is, and treats him as such. The secretary explains that nobody is supposed to win Motorama. She congratulates him on collecting the letter, but says that there will be no prize. Enraged, he realizes too late he has been deceived. A security guard throws him out of the skyscraper window.
He lands in a pool of water, and then emerges from the same river that he stopped at after the first diner. His car is good as new, and waiting for him on the dusty road. His health is also restored; his eye is back, his tattoo is gone. He throws away the metal leg extensions he made to enable him to drive the car and hitchhikes back towards home. En route, he finds the attendee Phil from the first gas station has survived being hit by the truck, but is severely injured. Lacking other options, Gus decides to stay there and work there to aid Phil. He is now back to being viewed as an adult, despite still being a child.
Gus later fills up the car of a gambler who claims to have just won a million dollars. He opens the trunk to show the cash to Gus. The gambler drives away, only to die from the same accident Phil endured, hitting a truck head-on. Gus remains at the desolate gas station with Phil.
