Vehicle paint is usually a 3 stage process. First, a grey primer is applied to the bare metal to improve paint adherence. Next, the coloured paint is applied. Last, a final layer of clearcoat or lacquer is added to add a layer of gloss and protection to the coloured paint.
Over time, your paintwork can become exposed to a number of external pollutants, all of which can cause physical damage to the top clearcoat layer, such as wash swirls, light scratches and chemical etching from bird droppings, This creates uneven areas which catch the light differently and are visible to the eye.