A method of manufacturing vehicles, comprising at least the steps of: providing a first shaped panel made of plastic material; providing a second shaped panel; coupling the first shaped panel to the second shaped panel so as to define a structural element of the vehicle, in which a hollow space is confined between the first shaped panel and the second shaped panel; before or during coupling, arranging conductive tracks in the hollow space, which conductive tracks define at least part of an electric equipment of the vehicle; filling the hollow space with polyurethane.