Which document is necessary for a vehicle before a smog inspection at a test only station?

The correct document necessary for a vehicle before a smog inspection at a test-only station is the Referee Label. This label indicates that the vehicle has been through a specific process to ensure compliance with emissions standards and that it requires a specialized inspection. The presence of a Referee Label signifies that the vehicle might have modifications or circumstances that need closer examination, which is crucial for the inspector at a test-only station to verify.

While other documents like a Repair History, Registration Card, and Owner's Manual can provide relevant information regarding the vehicle's past and its current registration status, they do not specifically pertain to the requirements for emissions inspection at a test-only facility. The Referee Label is directly linked to the emissions compliance process, making it essential for the inspector to carry out an accurate assessment of the vehicle's emissions system.