The objective to this bachelor degree project was to redesign a structure of the doors and add windows of a convertible car. This was carried out in collaboration with the company Hurtan Desarrollos S.L. To establish the requirements for the design, initial studies were performed: a literature review, a benchmark of related products and a study of standard car door designs. After this the final requirements were defined and the concept generation design phase was begun. In this phase a number of design methods were applied. The design concepts were systematically evaluated in respect to if, and to what degree, the concepts met the defined demands and needs of the design. The final concepts were completed with the demands of the company to obtain the results. In order to define, create and communicate ideas and solutions, the design was modelled in Solidworks software and exported to Creo Parametric 2.0 to create the final renders. Once the overall design was defined, materials and accessories were specified. The final result is presented in detail in photorealistic renderings and a physical design made by Hurtan Desarrollos S.L.