Unless the previous owner retained the original parts and provided them to us, we usually keep the existing modifications and clearly state in the report "includes non-original modifications." Since the standards for illegal modifications vary by country, buyers should assess whether these modifications can legally pass inspection in their destination country.

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).

A proper inspection relies on equipment, not just eyes. The inspector should use a paint thickness gauge to measure 50-60 points across body panels; original paint is typically 80-150 microns. An OBD diagnostic scanner reads stored and pending fault codes across all control units, and for EVs it also reads battery state of health and charge cycle counts. The car must go on a lift for the underbody check: frame rails, suspension components, oil leaks and accident repair marks are only visible from below. A battery tester checks starting voltage and charging system health, and a tread depth gauge documents tire condition. Ask for the report to include raw readings and dated photos rather than a simple pass/fail summary - that is what makes it verifiable.