Dried calcium marks on bodywork from lawn sprinkler. How do I remove them?

Our neighbour has been regularly watering (using a lawn sprinkler) a newly laid lawn. Our car, adjacent to their new turf, has been left with unsightly dried calcium deposits where the sun evaporated the water away. We are kicking ourselves as he asked if we wanted to move the car and we didn't. What would you suggest as to how to remove the marks. Many thanks for considering this question.

Asked on 7 October 2012 by SRAN

Answered by Honest John
Call in a professional valeter.
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