Processes involving use of reactive polymers received recently considerable attention also for producing components suitable for automotive structural applications. In particular polyurethane structural RIM technology seems to be the route of choice in terms of productivity, reliability and physico- mechanical performances in order to fit the automotive industry needs in the production of parts requiring superior load bearing properties. In this frame the development of long pot life snap-cure resins, fast and effective reinforcement preforming techniques as well as the development of computerized provisional processing methodologies are of paramount importance in view of industrialization of the technology. In this paper a description of the work carried out by Enichem Montedipe and Montedison is given. In particular a new family of PU systems, based on special isocyanate variants, is reported. These have been successfully tested on a full scale structural RIM plant including a continuous preforming unit, injection machine and molding equipment. Characterization data of medium size molded components and preliminary check of a computer aided processing model are also reported.