The concept of modular windows for automobiles has been established in Europe, Japan and the U.S.A. In this process the glass is encapsulated with a polyurethane elastomer using the Reaction Injection Moulding (R.I.M.) process. The module produced is designed for styling and aerodynamic improvements as well as simpler vehicle assembly since all the necessary components are incorporated, except for the sealant used in final assembly.Of major importance in defining a suitable material are the weatherability and glass adhesion characteristics of the polymer. In the present investigation the application of a two component aliphatic diisocyanate based paint system, by spraying into the mould prior to glass placement and injection of the polyurethane, can inhibit the degree of surface gloss reduction due to U.V. light under both artificial and natural light exposure. The selection of a suitable primer promotes good adhesion between the glass and polyurethane.