Vehicle License Tax Act Article 11

Owners or users of transportation equipment who obtain temporary license plates or automobile testing license plates shall be subject to tax calculation on a daily basis.For vehicles with temporary license plates obtained as mentioned in the preceding paragraph, the applicable tax amount shall be calculated based on the median of the tax amounts for various types of vehicles as specified in the Annex table of Article 6. For those who obtain automobile testing license plates, the applicable tax amount shall be calculated based on the highest tax amount listed for automobiles and motorcycles in the table.
中文原文 使用牌照稅法第11條
交通工具所有人或使用人領用臨時牌照或試車牌照者,其應納稅額,按日計算。
前項領用臨時牌照車輛之應納稅額,依第六條附表規定各類車輛稅額之中位數計算;領用試車牌照者之應納稅額,按表列汽車、機車之最高稅額計算之。

English translation for reference only; the Chinese text prevails. Not legal advice.