When buying a motor or gearbox, the car owner must provide the markings that are stamped on the part itself.

When buying any electronic part or control unit, you must provide the original part number. There is a nuance: on some foreign cars, the control unit has its own program with an additional number of firmware, so you need to check with the car mechanic whether this number is needed.

If the car is supposed to be bodily repaired, you need to know exactly the model of the vehicle. When buying auto parts in the online store, you can provide a photo of the original part.