Aravindh i also had the same problem while using NH4 , If you rub the surface it will be rough, some are visible and some aint visible, took it to 3M they told it could be taken off with treatment, I was given an estimate of 1750. I didnt do it right away since it was monsoon and my work in Vellore is till this month end so i have more trips on NH4 and thought will gather more such contaminants and finally get it cleaned. As Ramesh was mentioning its a daylight robbery, I just stumbled upon then thread now else would have told you. Anyways 3M is there for any contaminants on body always. - - - Merged Post - - - Interestingly i took it to car cares OMR the closest to my home and i was told it had to be done away with Sanding , i was quite apprehensive to do it a car thats barely 7 months old. It was constantly in my mind, i couldnt be peaceful, The next day i took off to work and went to 3M, Dushy is some one who brought my worries to rest told i can do it for sure with minimal treatment and after his words only i was relieved. Then gave me a choice its not an immediate thing to be done. you can do it at your time and convenience . Service and professionalism of 3M truly rocks.