In Pixar's Cars 3, Cruz Ramirez becomes Lightning McQueen's trainee and eventual race driver.
Cruz begins as Lightning's high-performance trainer at the Rust-eze Racing Center. She is technically skilled and enthusiastic, but she has never fulfilled her own ambition to compete as a top-level racer. Lightning initially sees her mainly as part of the program that is replacing him.
Their relationship changes during the film's journey through several training locations. Cruz learns from Lightning's experience, while Lightning realizes that her speed, courage, and racing instincts deserve a chance on the track.
By the climax, Cruz takes over as the Rust-eze racer and competes against Jackson Storm. Lightning adopts a mentor role, echoing Doc Hudson's influence on him. The ending therefore shifts the series from Lightning's rise to a new generation's opportunity.