Cars

Cars opens in the final race of the 2005 Piston Cup stock car racing season and championship in the Motor Speedway of the South, where a skilled but arrogant rookie racecar, Lightning McQueen (Owen Wilson), has overtaken his opponents, avoided a car accident, and built a large lead over two other prominent figures; the cup's defending (and soon retiring) nine-time champion, Strip "The King" Weathers (Richard Petty), and perennial runner-up and cheater Chick Hicks (Michael Keaton). Because of his refusal to make regular pit stops for new tires, opting only to refill his gasoline tank, Lightning's worn rear tires burst on the final lap, causing him to skid and ultimately crawl to the finish line, barely managing to tie The King and Chick Hicks in a photo finish. Race officials announce that, because the three racers are also tied in overall season points, they will compete in one final tiebreaker race to be held at the Los Angeles International Speedway, and give them one week to prepare.

While traveling down Interstate 40 to California, McQueen becomes separated from Mack (John Ratzenberger), his transport truck, and while trying to catch up he becomes lost on U.S. Route 66, catching the attention of the local sheriff (Michael Wallis) in the process. A chase ensues, during which McQueen crashes and gets tangled in wires, damaging part of the main street of a town called Radiator Springs. McQueen is taken to traffic court, where the town's attorney Sally Carerra (Bonnie Hunt) pleads against McQueen. He is sentenced to repave the road using "Bessie", a non-anthropomorphic asphalt-laying machine. McQueen attempts to escape to California, only to find that his gas tank is drained to a minimum, much to his dismay.

McQueen rushes through his first day of paving; as a result, the new road surface is so bumpy, uneven, and unusable that he is ordered to scrape it off and start again. The town's judge and doctor, Doc Hudson (Paul Newman), offers McQueen the chance to leave, provided that he outrace Doc in a race around Willy's Butte. McQueen eagerly accepts, and leaves Doc behind at the starting line, but loses control on a sharp turn in loose dirt and crashes into a cactus patch. Doc effortlessly cruises to the finish line, remarking that McQueen races as badly as he fixes roads. McQueen is forced to scrape the botched pavement clean and start paving again.

As the ensuing days pass, McQueen starts to befriend the town's residents, from whom he learns that Radiator Springs was once a thriving town until the completion of the nearby interstate highway, which bypassed the town, depriving it of its business traffic and visitors and ironically, depriving those passing visitors of the natural beauty found in the scenery along the old highway. He also learns that Sally had left behind a wealthy but unhappy life as a lawyer in California, and that Doc Hudson was once a famous racecar (the "Hudson Hornet", and a three-time Piston Cup champion at that). When Doc catches him looking at his trophies, McQueen asks the reason for which he abandoned racing in the first place. Doc, suddenly offended by this, shows McQueen a newspaper article and states that a crash in 1954 ended his racing career. Doc bitterly refuses to reveal much about his past, dismissing his old trophies as "a bunch of empty cups". McQueen comes to realize that the same racing world that brought Doc fame eventually destroyed him.

By the time McQueen finishes repaving Radiator Springs' main road, he has formed a friendly bond with the town and its residents. Rather than immediately leaving for California (as he had initially intended to do), he spends the day touring the town's businesses, receiving a fresh coat of paint, organic fuel, stickers for his bumper, and new tires in the process. When the town throws a cruise party that night, he is suddenly found by a multitude of journalists, then whisked away in his truck, Mack, without even a chance to bid farewell to Radiator Springs. The town's residents are sad to see him leave, while Sally, who has fallen in love with McQueen, is angry to learn that it was Doc who informed the media of McQueen's whereabouts.

The final race between McQueen, The King, and Chick Hicks is described by commentators Bob Cutlass and Darrel Cartrip as the "biggest race in history". Country Gas, East Honkers, and Ermyville are closed for the Dinoco 400, while nearly 200,000 cars watch the race at the racetrack. McQueen is distracted by his memories of Radiator Springs, losing time to the other racers. To his surprise, Doc arrives at the race, accompanied by others from Radiator Springs (except for Sally, Lizzy and Red who stayed behind to watch the race on TV), to serve as McQueen's pit crew. With Doc's coaching, a record-breakingly fast and efficient pit stop for new tires, and a few tricks learned from the small town's inhabitants, McQueen is able to get back into the race after being two laps behind .

As McQueen approaches the finish line, Chick sideswipes McQueen into the infield. McQueen initially skids through the infield, turning this skid into a controlled drift and heading into first place. Chick sideswipes The King in a desperate attempt to avoid finishing behind him, sending The King into a terrible rollover crash. McQueen sees this on the Jumbotron and fears that The King's racing career will end in the same way as Doc's had ended. McQueen comes to a full stop before the finish line, allowing Chick to cross. He then backtracks to push The King across the finish line ahead of him, saying that "I think The King should finish his last race" and quoting Doc's description of the trophy as "just an empty cup". Chick's official victory is hollow, as he is jeered and despised for taking out The King, while McQueen is cheered as a hero for his good sportsmanship. Dinoco corporation offers to sponsor McQueen, but he respectfully declines, saying that his current sponsor Rust-Eze gave him his big break and that as a result he wants to continue with them.

Two days after the race, McQueen returns to Radiator Springs, announcing that he will establish his racing headquarters there, helping to revitalize the town, with the once-abandoned Route being reclassified as "Historic Route 66."