Regulations Governing the Management of Import/Export Clearance for Transportation means Article 68
Additional equipment or critical machines or parts installed on a domestic vehicle outside the border must be declared with the Customs and import duty is paid upon entering the border.
中文原文 運輸工具進出口通關管理辦法第68條
本國車輛出境，如在國外增添設備或裝配重要機件，應於入境時向海關報繳進口稅費。