Originally Posted by joshs09slvrZ

If your fingernail catches on the scratch, you're going to need an aggressive polish such as 105. M205 is a finer polish (I use it as a middle polish) and can't really remove anything deeper than a swirl. Also, for what it's worth, M105 is very versatile in the sense that you can use it with a wool pad for the deep stuff (never use wool on our cars unless absolutely necessary), or you can use it with a mild polishing pad.