major part
(6) “major part” means— (A) the engine; (B) the transmission; (C) each door to the passenger compartment; (D) the hood; (E) the grille; (F) each bumper; (G) each front fender; (H) the deck lid, tailgate, or hatchback; (I) each rear quarter panel; (J) the trunk floor pan; (K) the frame or, for a unitized body, the supporting structure serving as the frame; and (L) any other part of a passenger motor vehicle that the Secretary of Transportation by regulation specifies as comparable in design or function to any of the parts listed in subclauses (A)–(K) of this clause.