Abstract: Conceptual design in the automotive industry is a time-consuming process. Iterations between concept sketches, created with traditional two dimensional methods, and 3D digital representations of a prototype are currently one of the big bottlenecks. In this paper we present a framework for an integrated 2D-3D design environment. The core of the framework is a model representing the characteristic lines of automotive shapes built from a set of example shapes. From every example shape we extract the same set of characteristic lines and represent them with a feature vector of deformation gradients. Given a set of constraints, our method can generate a new feature vector with an optimization procedure. We provide examples for meaningful manipulations. We demonstrate that these manipulations are intuitive and create plausible shapes.