Computer aid design (C.A.D.) shortens the development time of a model car considerably. With the computer data provided directly from the car manufacturer, the body contour can be replicated accurately in a short time. However, when developing classic cars, traditional method is still used because cars in the eighties or older were not designed by computer and no such material can be provided by the car makers. Normal development time for a scale 1:18 model with over 100 components is around ten months using traditional method. Computer aid design can cut two to three months of the development time. Model cars consist of many components, such as Pagani Zonda R with over 600 parts, the development time is more than 20 months even with the help of C.A.D.