People, common sence would tell you that it is NOT going to use the factory mounting holes. It is mounted on 2 posts. You can either get the body shop to fill and paint them, or you can find somebody with an LS the same color and trade them your trunk lid for thiers and not worry about it.
I would be all over this spoiler especially if it is $350ish painted but I know it will be more then that if you paint it. So $350 primed...HELL YEAH!