Car tuning jobs involve modifying the engine or body of a car to prepare it for a race or exhibition. An auto technician, or performance technician, alters the car’s engine or software to increase the car's speed, handling, or other measurable performance. Auto body specialists make cosmetic additions or changes to the body of the vehicle, such as body kits, spoilers, and side skirts. They may also add visuals using vinyl wraps, paint, or stencils. Car tuners often choose to specialize; they may focus on engine or body modifications, or they may specialize further and only modify certain manufacturers or types of cars.