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).

It's not mandatory. Four-wheel alignment and dynamic balance are part of routine maintenance. During long-distance towing and sea transport, the suspension may experience slight changes in stress. We recommend that buyers perform a four-wheel alignment locally after picking up the vehicle at the destination port and replacing tires suitable for local road conditions.

If insurance claims records are accessed, there will usually be notes like "the insured vehicle is fully responsible for hitting a fixed object" or "third-party liability insurance payment." We can roughly reconstruct the accident scene based on this and cross-verify the stress points on the vehicle's frame with paint thickness gauge data.