I. Definitions of special vehicles (SP) and retrofitted-vehicles The special vehicles in China are mainly fabricated by the so-called retrofitters. That is because in the management method in the past, vehicle manufacturers are classified into producers and retrofitters in terms of production power and whether the vehicles are reprocessed on the chassis made by other producers. Vehicle production enterprises refer to those who are qualified of development, OEM supplying, production capability and can produce complete vehicles one time. Retrofitters refer to those who mainly conduct reprocessing on purchased chassis for making complete vehicles. I. Definitions of special vehicles (SP) and retrofitted-vehicles The special vehicles in China are mainly fabricated by the so-called retrofitters. That is because in the management method in the past, vehicle manufacturers are classified into producers and retrofitters in terms of production power and whether the vehicles are reprocessed on the chassis made by other producers. Vehicle production enterprises refer to those who are qualified of development, OEM supplying, production capability and can produce complete vehicles one time. Retrofitters refer to those who mainly conduct reprocessing on purchased chassis for making complete vehicles.