Why do polished or chrome wheels get white or cloudy spots?

Polished aluminum without clear coat oxidizes when exposed to moisture, salt and harsh chemicals, producing dull, white or cloudy areas. On chrome, spots are often mineral deposits or pitting that starts where the plating is damaged. Use cleaners rated for the finish, dry the wheels after washing and protect them with a suitable sealant or coating. Bare polished aluminum may need metal polish to restore its shine.