Bump to an old thread.
I just removed the pinstriping off one of my vehicles yesterday. I don't know how old the pinstriping was, because the previous owner had the car repainted and restriped at some point. The car is metallic black, I'd guess it was resprayed 5 years ago or so.
After I pulled it off, I could see the lines where the pinstripes used to be (guess the rest of the paint has faded). I used 2.5 + orange cutting pad, SSR 1.0, + orange cutting pad, AIO, and Natty's, and the marks are barely noticeable. If I look closely, I think I can see the lines, but when I step a few feet away, the car looks great.