With reference to FIG. 1, the present invention provides a method of manufacture of an automobile structure comprising the steps of: forming in a die a plurality of castings (10) each having at least one socket (14); forming a plurality of metallic rails (12, 13) and fixing the metallic rails (13, 14) in the socket of the castings (10) in order to construct the automobile structure. The present invention also provides a method of manufacture of a plurality of different automobile structures, the method comprising: fixing metallic rails of a first plurality into sockets of a first plurality of the castings to form a first type of automobile structure; and fixing metallic rails of a second plurality into sockets of a second plurality of castings to form a second type of automobile structure. The invention also relates to automobile structures made by the methods.