Hey. its very simple to remove the cements spots but you have to keep patience while doing this. just take a water spray, same as used in hair cutting saloon, put one sache of shampoo in it, then get the used scrapper from the painter, just spray the shampoo water on the cement spot and remove it with the scraper, the angle between the scrapper and cement spot surface will not be more than 30 degree.
dont worry it will not get scratched the painted surface. myself did it sucessfully for my swift zxi.
Enjoy...