In the process of car body design, various surfaces can be generated from the given boundary curves. Depending upon the method of the surface generation and the quality of the boundary curves provided, the resulting surfaces may have global or local irregularities in many cases. Thus it would be necessary for the designer to evaluate the surface quality and to modify the surface or to use the different generation method based upon the evaluation results. This capability is very important because the defect of the surface quality detected in the production stage will require the rework on the dies and will cause a big loss in money and time. In this paper, two types of interrogation methods for the assessment of shape quality are described. One is the reflection mapping, which simulates the reflection test on the real part in the production line. This method is useful for detecting global irregularities of a surface. The other is the visualization of the curvature behavior of a surface. The method consists of traditional focal analysis, which exaggerates the mean, Gaussian and strain energy of curvature. This method makes it easier to detect local irregularities.