How can I tell if faded paint is oxidized or if the clear coat is failing?

Oxidation on single-stage paint, or light weathering on clear coat, typically looks dull and chalky but is still uniform and can often be improved by polishing. Clear coat failure looks different: cloudy, milky or white patches, flaking edges and peeling, usually starting on the roof, hood and trunk. Polishing cannot repair failing clear coat and may make it worse. Once the clear coat is peeling, the panel normally needs to be repainted.