Another factor which continues to play a significant role in the sales of Proton cars is the National Automotive Policy (NAP), enforced by the Malaysian government in the interests of Proton, Perodua, Naza and foreign brands with manufacturing plants in Malaysia. Under the NAP, imported vehicles are subjected to varying degrees of import and excise duties depending on the vehicle's origin of manufacture and engine displacement, with excise duty imposed at 60 to 105 percent being the highest component in the duty structure. Vehicles imported from members of the Association of South East Asian Nations, such as Thailand and Indonesia, are subject to the least import duties, whereas those from Europe suffer the worst. However, imported hybrid vehicles and cars purchased in duty-free Langkawi are exempted from the import and excise duties. The NAP ensures the survival of Proton and other Malaysian-made vehicles under a biased playing field in the Malaysian market. Nonetheless, the import duties of the NAP have been progressively revised and reduced in line with the eventual liberation of the market, but excise duties, the larger component of tariffs, continues to be high and opaquely applied, with non-tariff barriers effectively reducing the rate for Malaysian made vehicles.