The Tuner Cars are a group of street racers that cause mischief. They consist of Boost, DJ, Snot Rod, and Wingo. They play a prank on a drowsy Mack, causing Lightning McQueen to be released out onto Interstate 40 and ultimately end up in Radiator Springs, thus making the gang responsible for Lightning's disappearance. The gang ultimately gets their comeuppance when they make the mistake of speeding in Radiator Springs, causing them to be apprehended by Sheriff and remanded to the impound yard. They are then sentenced by Doc Hudson to pave roads in Radiator Springs using Bessie. In the Cars video game, a specific level relating to these characters is called "Delinquent Road Hazards", leading many fans to refer to their group by this name. They later appear in the short Tokyo Mater with the exception of Snot Rod.
The Tuner Cars also appear in Cars 2: The Video Game as playable characters.