A Knowledge Based Engineering (KBE) tool called ICAD, is being used to develop a design tool for automobile conceptual design. The design tool, known as AutoDSS, is based on an environment architecture which is known as a Design Support System (DSS). The Design Support System creates a virtual prototype of the automobile that includes all of the major assemblies including the exterior body shell, chassis, passengers, power train and running gear. The AutoDSS includes both a geometrical and non-geometrical description of the automobile. The components of the AutoDSS comprise a knowledge base, a high level graphics design environment, a feature based geometry modeler and a synthesis model.