Theory. If you decide to purchase a used foreign car and have chosen a specific model, then try to collect as much information about it as possible in advance. The best way to do this is to inspect a similar model in a showroom that sells new cars. First of all, find out where the identification number should be (VIN). The car may have additional VIN stickers (performed as decals), - find out where they are located.
Practice. So, you start to inspect the selected car. It is worth starting with checking the condition of the paintwork near the identification numbers. It should not differ in color and texture from the coating on the inside of the trunk, hood, engine compartment. soft surface (there is a trace of deformation even from the nail), paint streaks and uneven application - all this indicates that the place where the identification number is located was repainted. And repainting hides either the consequences of the accident, or traces of a number change. The coating near the number can be rubbed with a swab moistened with solvent: if the paint dissolves at least partially, this is a sure sign that it "not native".
Now directly about the numbers and identification plates. If the number is interrupted, the characteristic features of this operation remain: the metal surface is most often deformed, slightly convex or concave. With the artisanal method of interrupting, a double contour is often noticeable; the signs are not on the same straight line, but "jump", they have different indentation depth; between letters or numbers - gaps of different sizes. Pay special attention to the same signs. They should not differ from each other in shape or size. Another important point: if you notice any characteristic feature on the same signs in the numbers, be sure that these signs are not factory ones. The company number is applied with a single stamp, "handicraftsman" for each number or letter uses a separate stamp and repeats the characteristic "mistake".
Harder to identify "criminal" car, when the number is replaced together with the part or that part of it on which it is embossed. As a rule, in this case, the number is the factory number. Therefore, it is necessary to inspect the attachment points of this part to the body. A simple way to detect such a substitution would be to tap. You should be alerted if the sound when tapping is deaf, "wood" or rattling. It is worth remembering that in cars, individual parts of the body are fastened by resistance welding. Connection points are usually points with a diameter of 5–6 mm. If at the attachment points "license plate" parts to the body have traces of a different type of welding, and their surfaces are also deformed - which means that the part is not fixed to the body in a factory way.
When inspecting the engine, pay attention to the area with the number: it should be flat, and the signs on it should be clearly and brightly embossed, without double contours. By the way, the site itself is machined on a milling machine, from which traces remain in the form of semicircles. They are clearly visible even with severe corrosion.
The described signs are quite easy to identify even for a non-professional. There are others, but they can only be identified by experts. You should contact them if you have any doubts.