Initially, I used it on a 10-year-old white car with several small marks mainly caused by flies that sat on the car when the sun hit it and filled it with their droppings, as well as other unknown marks. The clay bar is supposed to remove these marks from the paint. It was my first time using clay, and due to the brand, I expected it to work wonders. I can say that it removed a satisfactory amount of dirt from the paint and easily removed surface marks. However, for more stubborn marks, it required a lot of handwork, multiple passes, and significant force (while it should normally be worked gently) to remove them, and many marks were not removed at all. Personally, I used the same brand's soap as a lubricant in spray form, rather than Meguiar's quick detailer (a specific spray). I don't know if this spray plays such a significant role, although I would have liked to try it to see if it makes a difference, even though I don't think it does. What I was quite satisfied with is that I was able to cover the entire car with half of the material (25g), and it is still clean enough to be used again. Maybe I didn't work with it properly, but I had watched several videos on YouTube before purchasing it to do it as well as I could. Overall, the color became vibrant and less dull, but the marks I wanted to remove did not disappear.