In Pixar's Cars (2006), Lightning McQueen's truck-and-trailer friend is named Mack.
Mack is a red transport truck who carries McQueen and his racing equipment between events. He is dependable and hardworking, but he becomes exhausted during the overnight drive to California. When he is distracted by a television broadcast, McQueen falls from the trailer without Mack noticing.
The separation starts the film's central chain of events. McQueen is later found in Radiator Springs, while Mack continues toward the race venue. Their reunion helps explain why McQueen arrives at the tiebreaker later than expected. Mack is also one of the few characters who regularly interacts with the wider racing world outside the small town.
Mack is sometimes confused with Mater because both are important companions associated with McQueen. Mater is the rusty tow truck from Radiator Springs, while Mack is the articulated transport truck. Mack also appears in later Cars films and related short-form material, continuing his role as McQueen's hauler.