I'm seeing splotches on my car's chromed parts that don't wash or rub off. The manager at my detailer pointed the problem out to me and said he thinks it's due to the magnesium chloride they use on the roads after a snowstorm; it seems plausible, since only the chromed parts down low and on the rear end are affected (the big chromed rings around the side windows are fine). Anyone else seen this, or have suggestions about removing the spots?