An inclined engagement surface of an elastic engagement hook is elastically engaged
with an engaged section in a state of being inclined with respect to a roof panel.
As a result, it is possible to absorb an error of a three-dimensional relative
positional relation between the elastic engagement hook and the engaged section.
That is, the error of the relative positional relation in two directions (an X
direction and a Y direction in FIG. 5B) can be absorbed by a deflection
of the inclined engagement surface, and the error of the relative positional relation
in remaining one direction (a Z direction in FIG. 5B) can be absorbed by
a slip between the inclined engagement surface and the engaged section.
