Contamination from agricultural and horticultural sprays. The problem is seasonal/regional and affected by bird/insect population. The organic etching is accelerated by intensified heat, such as from sunlight. Time and temperature dramatically increases concentration of acid. The damage is more visible on dark or darker colors due to heat absorption.

Acid rain is the term given to rain containing effluents from manufacturing, chemical industries and particularly power stations. Some of the effluents may be acidic or alkaline in the presence of water (e.g. sulphur dioxide will dissolve in water to give an acidic solution, whilst a mixture of cement dust and water is strongly alkaline).

Avoid contaminated atmosphere.

Frequent washing is the best safeguard against unseen contaminants.

Maintain and protect the topcoat of the vehicle using a non-silicone containing polish or wax.

Immediately clean and neutralize the contamination with mild detergent and water before etching starts.

Wash the vehicle very carefully with detergent and water using a brush and lots of water to neutralize the contamination.

Rub affected areas with rubbing compound and polish.

In severe cases, sand the areas needed and be sure the craters are sanded away completely before using primer and topcoat.