Shadowline Trim
Exterior trim may become discoloured; this discolouration is due to a film deposited on the trim which distorts the light reflecting off the trim. These deposits may come from car washes, hard water, or other environmental conditions. Deposits that cause the discoloration can be easily removed by polishing with a quality light finishing polish (Extract from a BMW technical service bulletin (TSB)
Note: The glossy black trim pieces are
anodized, not painted, and the discoloration does not mean that the surface has been damaged. Therefore, the trim pieces do not need to replaced.