One fucking hard product to get off a car. I was bored last night and wanted to do 3 coats of Z well because I was bored . So as I was mixing her up (God that is getting old, I will not be buying ZFX again) I thought what the hell how about a few blasts of ZCS and lets see what happens. Yeah it looks amazing as Z always does for me but it felt like I left a little of the old #16 on the paint for about 2 days and then tried to get it off. Note to self, chemicals are mixed by professionals for a reason. On a lighter note my eyebrows are starting to grow back already.