In all the housing societies in Mumbai & Thane cities the car is washed using borewell water. Over a period of time it leaves a heavy stain on car windows which is difficult to remove.

I have tried many stain removers but all in vain. The car service centres also do not have a solution to this problem and they have suggested to stop using borewell water or reduce the frequency of car wash to once a week from daily. 

Is there any sure-shot solution to get rid of these stains?