I've never used the pen, but I've read varied results. I would recommend the BMW touch up kit, applied by a angled cut butt end of a match and lightly dabbed on. After 24 hours put on another coat so it dries above
the level of the rest of the paint. Then get a very very fine grit sand paper and cut out a circle the size of a pencil eraser and attach it to.... a pencil eraser. Gently wetsand the paint by spinning the pencil until the paint is smooth w/ the rest of the paint and then polish.
Or try the pen and get back to us should I ever have to fix a chip on the new M3