26 C.F.R. § 48.4071-4
The tax imposed by section 4071(a) applies with respect to tires and inner tubes (other than bicycle tires and inner tubes) that are original equipment for an imported article upon which no tax is imposed under section 4061 if the article is sold on or after December 11, 1971. In such a case, the importer of the article is treated as the manufacturer and vendor of the tires and inner tubes with which the article is equipped. However, the tax imposed by section 4071(a) is not imposed with respect to tires and inner tubes if the imported article is an automobile bus chassis or an automobile bus body. Solely for purposes of this section, the provisions of section 4218 (relating to use by a manufacturer or importer considered a sale) do not apply in cases where an individual imports an article having original equipment tires and tubes and on which article no tax is imposed under section 4061 if the article is imported solely for the individual's personal use and is so used.
26 C.F.R. §48.4071-4
Secs. 4071(b), 4071(c), 4073(c), and 7805, Internal Revenue Code of 1954. (80 Stat. 331, 26 U.S.C. 4071(b) ; 68A Stat. 482, 26 U.S.C. 4071(c) ; 70 Stat. 389, 26 U.S.C. 4073(c) ; 68A Stat. 917, 26 U.S.C. 7805 )