Enforcement Rules of the Estate and Gift Tax Act Article 26
For vehicles, vessels, and aircrafts, the value shall be determined by deducting a reasonable depreciation amount from the original cost. In the event of failure to present the proof of original cost or where apparent inconsistency exists between the proof of original cost presented and the facts, the value may be determined according to the year model and the actual usage of the item concerned.
中文原文 遺產及贈與稅法施行細則第26條
車輛、船舶、航空器之價值，以其原始成本減除合理折舊之餘額為準，其不能提出原始成本之證明或提出原始成本之證明而與事實顯不相符者，得按其年式及使用情形估定。