The headliner is considered an "irreversible interior component." If the edges are delaminated or there are deep, hard-to-clean dark water stains, it will directly lead to a downgrade in the interior grade, even if it does not affect driving. We will not use pins or low-quality glue for cosmetic repairs.

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).

Absolutely. The extreme temperature fluctuations will significantly accelerate the aging of chassis rubber parts, oil seals, and interior plastics. For vehicles frequently dispatched across such latitudes, we will conduct fatigue resistance checks on chassis rubber parts that are twice as stringent as those for vehicles in temperate regions.