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).

This involves personal privacy, and we have no right or ability to retrieve personal driving violation records from the traffic police system. We can only infer if there was aggressive driving by checking if the engine has been reprogrammed with a higher-level ECU (stage 1/2) or if the transmission has a history of severe overheating.

Air suspension is very delicate. If, after the vehicle has been stationary for about 12 hours, the height on one side of the vehicle drops more than 1.5 cm when measured from the wheel arch to the tire, we will determine that there is a slight air leak in the air spring or distribution valve on that side and warn you of the high subsequent repair costs.