Thermo King Corporation v. The United States

If we look only at the skin of the automotive-tax statute and regulations, we are forced, I think, to rule that plaintiff’s equipment is covered. Section 4061(b) of the 1954 Code levies the tax on sales of “parts and accessories” of trailers and semitrailers. The regulation (Treas.Reg. § 40.4061 (b)-2) includes within “parts and accessories” articles primarily designed to improve a truck (or chassis) or to be attached to it in order to add to its utility, whether or not the article is essential to operation or use. The first example given is an “automobile air conditioner." From the…