Mack is the Rusty Rust-Eze truck. He is voiced by John Ratzenberger.
"Endless days on the road and sleepless nights criss-crossing the country... For some this life would quickly grow old. But not Mack. No sir. Mack knows how important his role is. He's driving Lightning McQueen, the world's fastest racecar. He's part of a team, and everybody knows there's no I in team, just like there's no I in Mack."
In the video game, he appears in part 2 of the end-scene for Radiator Springs Grand Prix, where he tells Lightning that he should get back into shape for racing before the next season starts. He then appears in all the cut-scenes for the Piston Cup Races. In High Speed Heist, the Delinquent Road Hazards rob him. Then Mack reports to Sheriff that he was robbed, and Sheriff tells Lightning about the robbery. Then in the cut-scene for Los Angeles International Speedway, Mack was kind of sad, because it was the end of the season, and he was gonna miss the season.
He doesn't play a big role in Cars Race-O-Rama. He appears in Mack Track Challenge, where you must use his trailer to do a big jump. Mostly in the game, he is the transporter that helps you get to different places in the game.
Mack is Lightning McQueen’s trusted long-haul driver, crisscrossing the country from race to race, always with a smile on his grill. After dropping Lightning off in Radiator Springs with his fourth Piston Cup championship trophy, Mack sets off with the rest of the pit crew for a well-deserved vacation. Who knew that Lightning would end up jetting off to a race around the globe in the World Grand Prix?
In the Film
In the film he is briefly seen at the beginning when Lightning goes back to Radiator Springs, where he says one of his only 2 lines. He doesn't accompany him to the World Grand Prix due to being on vacation. At the end, he talks with Lizzie and says the other of his only 2 lines of the movie.
Those only 2 lines that he had are "Oh, these best friend greetings all get longer every year," and "Oh, those 2 are perfect for each other."
Mack's only appearance in Cars Land is in Radiator Springs Racers. When you come in the dark tunnel, you will almost crash into Mack, so you drive out of the way. You can hear him scream and call you a road hog. Then you will almost crash into Van and Minny who really are the car couple that are lost and need to look for directions.