I've done it before and it is a pain to make it look right. I had a nice huge nick from a rock on my right fender. I was told by the dealer to apply it in VERY LIGHT coats. Put as many coats as you feel necessary, but do them lightly. Also, make sure the nick is clean. You don't want dirt in there. It doesn't look perfect, but at least the color matches fairly closely so I don't notice it much anymore. Your car color code is on your door frame next to your seat when you open the door.