In Pixar's Cars 3, the Rust-eze owner who hires Cruz Ramirez is Sterling.
Sterling is a wealthy businessman who purchases Rust-eze and manages Lightning McQueen's comeback after the champion's crash. He assigns Cruz Ramirez to train Lightning at the Rust-eze Racing Center, a high-tech facility filled with simulators and other modern training equipment.
The character reflects the business pressure surrounding professional racing. Sterling wants Lightning to return successfully, but he also has a commercial plan for the future of the team. His proposal eventually pushes Lightning toward a different role in the sport and helps set up the film's final act.
Sterling is voiced by Nathan Fillion. He should not be confused with Tex Dinoco, another wealthy racing-world figure, or Miles Axlerod, the organizer and antagonist associated with Cars 2. Smokey is also a different character: Doc Hudson's former crew chief and mentor in Cars 3.