In a vehicle body inspection, your job is to be a good detective. Look for clues, find them and combine them in a way that tells the story of how the car came to be in the condition it is in after leaving the factory in perfect condition. This can also help you find problems in a car you already have that haven't yet revealed secrets hidden beneath the surface. Alternatively, you can get an elometer or paint thickness gauge.
Check the thickness of the car's paint layer and large variations lead to irregularities. If you see signs of minor imperfections in an area and the owner confirms that the car had a minor collision in the parking lot in the past, that means that there probably hasn't been any major structural damage and that the owner is honest.