In the small, mid-western town of Grandview, high school senior Tim Pearson borrows his father’s Cadillac to take Bonnie Clark to the prom. During the evening, Tim and Bonnie leave the dance to park in a secluded area, next to a stream. As the couple makes out in the back seat, the Cadillac begins to sink into the boggy ground. With his tuxedo splattered in mud, Tim walks to Cody’s Speedrome demolition derby and enlists the help of owner Michelle “Mike” Cody, who has a tow truck. In the meantime, Bonnie telephones her father, who meets the couple at the derby and punches Tim in the stomach for trying to seduce his daughter. Michelle Cody defends the young man, until she finds out Tim is the son of devious realtor and county commissioner Roger Pearson, who has attempted to acquire the derby property ever since Michelle’s father died. She asks her good friend, Ernie “Slam” Webster, a popular derby competitor, to tow the Cadillac instead. While her mother, Betty Welles, counts the small proceeds from that evening, Michelle worries about her struggling business, exacerbated by recent county inspection violations. After their encounter, Tim is captivated by the beautiful Michelle, and fantasizes about starring in a music video with her. Returning to the Speedrome, he meets Michelle’s mentally handicapped brother, “Cowboy,” who drives the forklift. Tim wants to compete in the derby, but Michelle dismisses the overeager teenager. After the bank refuses her loan request, Michelle asks her uncle, bar owner Bob Cody, for $10,000, but he is only able to give her $500. While at the bar, Michelle encounters an intoxicated Slam, who suspects his flirtatious wife, Candy, is having an affair. As Michelle offers to help Slam home, he confesses to being infatuated with her during their high school years. However, Michelle appears reluctant to admit her own complex feelings for Slam. Suffering a hangover the next day, Slam leaves his job as a bulldozer operator to go home early, and is enraged to find Candy frolicking with salesman, Donny Vinton. After Slam vandalizes Donny’s car, Candy kicks her husband out of the house and files a restraining order against him. Slam takes refuge at the Speedrome, and Michelle tells her friend he does not love Candy, but is merely afraid of being alone. Later, Slam appears nervous as he invites Michelle to dinner. Although pleased, she must postpone on account of a county commissioners meeting that night and suggests they have drinks after the next derby. Tim joins his father at the meeting for an official photo and reveals that he wants to study oceanography in Florida rather than accept a scholarship from a local college. Mr. Pearson is opposed to the idea and tells Tim they will discuss the matter later. During her presentation to the county board, Michelle appeals for more time to comply with violations, but the members are reluctant. Desperate, she accuses Pearson of trying to force her out of business by buying all the property surrounding the Speedrome. Meanwhile, Tim goes to his father’s office to retrieve an item and finds plans to build a private country club on the derby property. He interrupts the meeting to show the board the blueprints, infuriating his father for jeopardizing a lucrative deal. After the meeting, Tim does not want to go home, and an appreciative Michelle invites him to her place. He is eager to leave the small town and is surprised to hear the twenty-seven-year-old Michelle moved back to Grandview after divorcing her husband. During the evening, the two have sex and Michelle offers to let Tim drive in tomorrow’s derby. Tim informs Michelle that immediately after graduation he plans to teach at a Scuba diving school in nearby Chicago, Illinois, so he can earn enough money to study dolphins in Florida. In the morning, Slam arrives at the trailer unexpectedly and storms out as soon as he sees Tim in Michelle’s bedroom. On the last day of high school, Tim announces he is leaving for Chicago to pursue his own interests. His father apologizes for his aggressive business tactics, and suggests Tim try the local college for a year before pursuing oceanography. However, Tim refuses. When a buyer arrives to pick up demolition cars at the Speedrome, Cowboy throws a tantrum and attacks the forklift operator, screaming that the cars belong to him. Michelle regrets not telling her brother about the sale. Before the derby starts that night, Michelle suspects the jealous Slam Webster will target Tim’s car and gives the teenager some last minute advice. Meanwhile, her attempt to reconcile with Slam fails. During the competition, Slam topples Tim’s car, not realizing that the boy’s vehicle was already out of commission. Although Slam is apologetic and Tim has only a minor injury, Michelle kicks Slam out of the race for unfair play. Exasperated, the hot-tempered Slam leaves the derby and plows through his house with a bulldozer while Candy Webster and Donny Vinton are inside. Police arrive to arrest Slam, while the two lovers scramble from the bedroom in their underwear. As Michelle takes Tim to the hospital for treatment, she admits she loves Slam. Back at the Speedrome, Michelle and Tim find the entire place engulfed in flames. When his father shows up at the site the next morning, Tim accuses him of starting the fire, but Mr. Pearson denies responsibility. The firemen discover the padlock to a gas valve was unlocked, and Michelle confronts her brother who is the only other person with a key. An emotional Cowboy admits to the wrongdoing, complaining that she took his cars away. Despite losing their home as well as their business, Michelle and her mother embrace the troubled boy. Tim apologizes to his father and rides home with him. When Michelle bails Slam out of jail, the two kiss and appear ready to embark on a relationship. Michelle mentions she might finally get a fair deal and sell the property to Pearson, allowing them to start a new life together. Later, Tim says goodbye to his family before boarding the bus for Chicago. As the bus leaves town, Slam and Michelle intercept it and pull Tim off. Handing him some cash and keys to an old Studebaker, the two instruct the high school graduate to skip Chicago and go directly to Florida to study dolphins.