In Pixar’s Cars 3, Cruz Ramirez takes over racing for Lightning McQueen at the final race.
Cruz is introduced as Lightning’s trainer at the Rust-eze Racing Center. She is a bright yellow sports coupe with advanced training knowledge, but she initially believes she belongs in a simulator rather than on a professional racing circuit.
During the Florida 500, Lightning realizes that Cruz has the speed, skill, and determination needed to compete. He gives her his racing number and lets her enter the race. Cruz then finishes the competition and begins a new professional chapter as a racer, while Lightning adopts a mentoring role.
Sally Carrera is Lightning’s friend in Radiator Springs. Holley Shiftwell is a British spy from Cars 2, and Flo runs the local café. None of those characters replaces Lightning in the final race of Cars 3.