A car body structure is dipped into an electro-immersion lacquering liquid, and a voltage is applied to the body structure to provide it with a base coating. The structure is taken out of the lacquering liquid, and is afresh provided with a top coating by electro-immersion lacquering. Finally it is provided with a layer of clear lacquer. The layer of clear lacquer is chemically hardened first by infrared radiation and then by convection drying.
