A more sophisticated or "fancy" term for an auto mechanic is "automotive technician" or "automotive engineer." These terms emphasize the technical and specialized skills required in the field, reflecting the advanced knowledge of modern vehicle systems, diagnostics, and repair techniques.

In professional or formal contexts, "automotive service technician" or "vehicle maintenance specialist" might also be used to convey a higher level of expertise and professionalism. These terms highlight the evolving nature of the profession, which now involves working with complex computer systems, electrical components, and advanced mechanical systems in modern vehicles.

For those specializing in high-performance or luxury vehicles, titles like "master technician" or "performance vehicle specialist" might be employed to denote a higher level of skill and specialization.

Ultimately, the choice of terminology depends on the context and the level of sophistication one wishes to convey.