In From a Buick 8, the mysterious car is discovered by Troop D of the Pennsylvania State Police. The troop's members keep the Buick hidden and gradually piece together its disturbing history.
The car appears in 1979, when a mysterious driver leaves a blue 1953 Buick Roadmaster at a gas station and disappears. Troopers from Troop D investigate after the attendant reports it. They soon realize that the vehicle is not an ordinary Buick: its controls are useless, its engine has no normal moving parts, and it can repair damage to itself. The car also produces strange flashes and seems connected to another world.
The novel is framed through recollections shared by Troop D officers, especially Sandy Dearborn, with Ned Wilcox, the son of a dead trooper. Troop D is therefore both the investigating unit and the story's emotional center. Readers may remember the book's title car or Pennsylvania setting, but the canonical troop designation is D—not Troops A, B, or C.