Lighting McQueen is the main character of all the movies in the trilogy and is at first a selfish racer who only cares about winning. Through his time at Radiator Springs, he learns to prioritize friends over career glory.
Mator didn't have any friends before Lighting came. He is very funny and lively. He may not be the smartest but he is a great friend to everyone. Mator is McQueen's biggest fan and will always support him.
At a grumpy old guy who does not like McQueen much at first. He works at a medical clinic in town and he teaches McQueen how to race smart, not just fast. He teaches him how to drift and not be selfish.
Sally is a nice person who owns and runs the Cozy Cone Hotel. Through McQueen's time at Radiator Springs, she takes McQueen on a ride through the wilderness. She later becomes his girlfriend. She is very supportive and likes racing.
Mack is McQueen's ride to all his races. He takes his job seriously and supports McQueen through his hard times. He fell asleep on the job because McQueen wanted to get to California with no stops. He is a very nice and fun person.
McQueen's biggest competitor in becoming the new face of Dinoco. He races dirty and only cares for his well being. He will cheat to get ahead in a race, like purposefully making others crash and more just to get ahead in the race.