Business process re-engineering is becoming a main focus in today's efforts to overcome problems and deficits in the automotive and aerospace industries (e.g., integration in international markets, product complexity, increasing number of product variants, reduction in product development time and cost). In this paper, we investigate the steps needed to apply virtual reality (VR) for virtual prototyping (VP) to verify assembly and maintenance processes. After a review of today's business process in vehicle prototyping, we discuss CAD-VR data integration and identify new requirements for design quality. We present several new interaction paradigms so that engineers and designers can experiment naturally with the prototype. Finally, a user survey evaluates some of the paradigms and the acceptance and feasibility of virtual prototyping for our key process. The results show that VR will play an important role for VP in the near future. Key words: Virtual environments, virtual pr...