In a method for the composition of a box-shaped body (2), the assumption is made of a flat expansion of the box-shaped body, which expansion is constructed as a coherent entity of walls (3-6) which are movable with respect to each other, whereupon the walls (3,5,6) are folded and the box-shaped body (2) is formed. The edges of the walls are thereby brought together and affixed to each other by means of gluing with, preferably, a two-component glue. The flat expansion of the box-shaped body (2) is usually made by means of the injection moulding of a plastic material. The box-shaped body (2) which is constructed in accordance with this method has walls which stand perpendicularly with respect to each other, a fact which makes the box-shaped body particularly suitable for use in a car for the fitting of accessories such as audio equipment, car radios, cassette players, etc. A vibration-free fitting without additional aids is simplified by the perpendicular running of the walls.