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).

We do not rely on the seller's verbal assurances. We provide multi-dimensional accident-free certification by cross-referencing insurance claims records, service orders from authorized dealerships, and conducting on-site paint thickness measurements and weld point inspections of the chassis and structural components (longitudinal beams, A/B/C pillars, shock absorber mounts).

We will never perform blind deep disassembly unless there are clear severe fault codes or extreme noises. The sealing of the engine and transmission is crucial, and compromising the factory seals to investigate non-existent issues is unprofessional. We rely on data flow and external acoustic and fluid analysis to make judgments.