Abstract: The present invention relates to a process for producing a durable multi-layered coating on difficult-to-coat substrates, such as aluminum. The process includes subjecting the surface of the difficult-to-coat substrate to a adhesion promoting step, followed by applying an intermediate layer of flexible primer, which contains a polyester copolymer produced through a two-stage polymerization process. A mar resistant top layer of clear coating composition is then applied over the intermediate layer to produce the multi-layered durable coating on the difficult-to-coat substrate. If desired, the intermediate layer may be pigmented or it may be applied in the form of one or more patterned layers of different colors. Alternatively, one or more patterned layers of different colors may be applied over the intermediate layer before the application of the mar resistant top layer.