We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).

During the stationary steering test, the technician will check the smoothness of the steering wheel from full left to full right, looking for any unusual noises from the steering gear; they will also inspect the hydraulic power steering pump (if present) and the seals of the steering column for any hydraulic fluid leakage.

We use an internationally certified electronic signature platform (such as DocuSign or Adobe Sign). Each signed contract generates a digital certificate with a timestamp and encrypted hash value, which has full legal defense effectiveness in international arbitration courts.