The Delinquent Road Hazards are the secondary antagonists of the 2006 Disney•Pixar animated film Cars. They are a group of four cars that intentionally cause danger on the highway: Boost (purple neon/silver Nissan Silvia (S15) with a custom body kit resembling JGTC cars, voiced by Jonas Rivera), Devon "DJ" Montgomery Johnston III (blue customized/slammed Suzuki Sidekick/Geo Tracker three-door SUV, voiced by E.J. Holowicki), Wingo (green and purple 2004 Acura RSX, voiced by Adrian Ochoa), and Snot Rod (orange Dodge Challenger with a blower, voiced by Lou Romano).
The Tuner Cars catch Mack nodding off to sleep on the way to California. They amuse themselves by playing a prank on a drowsy Mack, by putting him to sleep with soothing music (Kenny G's "Songbird"), and nudging him onto the rumble strips along the shoulder. The resulting vibration causes Mack's trailer door to open and a sleeping McQueen to roll out of the trailer. When the chronically-sniffly Snot Rod sneezes, Mack is startled awake and the Tuner Cars accelerate away, leaving the still-sleeping McQueen behind out on the highway near Radiator Springs, thus making the Tuner Cars mostly responsible for McQueen's disappearance.
The gang ultimately gets their comeuppance during the end credits of the movie when they make the mistake of speeding in Radiator Springs, causing them to be apprehended by the Sheriff for reckless driving and destruction of property and remanded to the impound yard to do their time. It is then later revealed that Doc Hudson himself sentenced the Tuner Cars to messy roadwork of towing Bessie for their actions. It could be implied that they would be released from Radiator Springs for good behavior if they fixed the road.
The Tuner Cars later appear in the short Tokyo Mater with the exception of Snot Rod. They did another reckless driving causing Sheriff to chase them.
In the Cars video game, two specific levels relating to the Tuner Cars are called "Delinquent Road Hazards" and "High Speed Heist".
In Delinquent Road Hazards, McQueen tries to enter Tailfin Pass only to find them blocking the road. Boost tells McQueen that the road is closed but McQueen believes its okay. DJ then responds that its closed to McQueen, in which he finds out that the word meant to get lost. McQueen then challenges the tuner cars that if he wins, they let him pass.
The Tuner Cars are downloadable playable characters.
Out of the cars, only DJ appears in Cars Land at Disney California Adventure, where he plays songs for the guests as part of hosting his daily dance activity, DJ's Dance n Drive. This show and DJ himself would be relocated to Disney's Hollywood Studios as additional entertainment outside Lightning McQueen's Racing Academy.
- In Italy, Boost and DJ are voiced respectively by F1 racers Giancarlo Fisichella and Jarno Trulli, while Wingo is dubbed by 24 Hours of Le Mans racer Emanuele Pirro.
- Snot Rod was supposed to be in the unmade Cars Toons episode, Import Mater. This episode was later remade into Tokyo Mater, in which he didn't appear.
- Wingo was the only Delinquent Road Hazards member that was playable in Arcade Mode in Cars: The Video Game, despite Boost and DJ being playable in the High Speed Heist minigame.
- A repainted, non-anthropomorphic version of Boost could be seen on a poster on the wall of Andy's room in the trailer of Toy Story 3. This poster was replaced in the final movie by a picture of Finn McMissile.
- While DJ's license plate states that his hometown is Treble Town, he has come to visit Tokyo in Tokyo Mater depicts him as one of Tokyo's residents, making it unclear where DJ's true town of origin is.
- If they haven't tricked Mack into falling asleep, McQueen would never end up in Radiator Springs where he would be taught humility and how friendship is more important in life than racing and winning.
- DJ's original die-cast depicted him with blue stripes rather than green. This was corrected in 2009, but the incorrect striping returned on his 2015 re-release.
- The song DJ plays in his introduction is "Rollin' in the Rearview" by Headbone and Jabu; he later plays "Songbird" by Kenny G to put Mack to sleep.