The term OEM stands for Original Equipment Manufacturer. What does that really mean? It means that the part was made by a company that is a subcontractor to a vehicle manufacturer. It DOES NOT mean the part was made by the manufacturer.Some examples; 1  Most fuel parts on a VW are made by Bosch. 2  This means that Bosch is the OEM for VW regardless of where you buy the Bosch part it is still OEM.t means that the part was made by a company that is a subcontractor to a vehicle manufacturer. It DOES NOT mean the part was made by the manufacturer. Some examples; 1  Most fuel parts on a VW are made by Bosch. 2  This means that Bosch is the OEM for VW regardless of where you buy the Bosch part it is still OEM.