Abstract: A waterbased coating composition containing about 10-30% by weight of film forming binder dispersed in an aqueous carrier; wherein the binder containsa. an acrylic silane polymer of polymerized monomers of alkyl methacrylate, alkyl acrylate or mixtures thereof, a silane containing alkyl acrylate or methacrylate and the polymer has an acid no. of 2-100 and a hydroxyl no. of up to 100, a glass transition temperature of -40 to 25 C. and a weight average molecular weight of 500,000 to 3,000,000; andb. a polyurethane selected from the following group: polyester urethane, polyether urethane or polyacrylourethane;the composition is useful for painting and refinishing the exterior of automobiles and trucks.