A strengthening member for an automobile includes a cellular structure having a plurality of cells. A cross section of each cell has eight sidewalls interconnected at eight corners to define a closed polygon. The sidewalls define eight internal angles located at the corners. Two of the internal angles are acute and two of the internal angles are reflex.

A side pillar air curtain guide includes a main body having a ramp receiver and an air curtain ramp insert connected to the main body. The air curtain ramp receiver insert includes a plurality of ribs projecting from the main body at an acute included angle with the main body.

A side pillar air curtain guide includes a main body having a ramp receiver and an air curtain ramp insert connected to the main body. The air curtain ramp insert is of honeycomb construction.

A shock absorber to be mounted on a vehicular exterior side of a trim member includes a plate member having a plate surface and to be mounted on a vehicular exterior surface of the trim member such that the plate surface of the plate member is along the vehicular exterior surface of the trim member, and at least two or more shock absorbing members that are arranged on a vehicular exterior surface of the plate member to be spaced from each other along the plate surface of the plate member.

A side pillar air curtain guide includes a main body having a ramp receiver and an air curtain ramp insert connected to the ramp receiver. The main body is made from a first material having a strength S.sub.1 and a ductility D.sub.1 while the air curtain ramp insert is made from a second material having a strength S.sub.2 and a ductility D.sub.2 where S.sub.1>S.sub.2 and D.sub.1<D.sub.2.

A side pillar air curtain guide includes a main body having a ramp receiver and an air curtain ramp insert connected to the ramp receiver. The main body is made from a first material having a strength S.sub.1 and a ductility D.sub.1 while the air curtain ramp insert is made from a second material having a strength S.sub.2 and a ductility D.sub.2 where S.sub.1>S.sub.2 and D.sub.1<D.sub.2.

The shock absorber includes: a base portion fixed to the attachment target; a shock absorbing portion having flexibility and attached to the base portion so as to be reversibly switchable between a housed state in which the shock absorbing portion is retracted toward the base portion and a protruding state in which the shock absorbing portion protrudes from the base portion; and a drive unit driving the shock absorbing portion to reversibly switch between the housed state and the protruding state. The drive unit, when operating the shock absorbing portion, at least switches the shock absorbing portion from the housed state to the protruding state.