I've been using the same cutting compound for three or more years. M-100 then 205. It's working fine but with some cars I just can't seem to get a mirror finish. I mean 100% scratch free. I know most clients don't want that type of finish. But I feel like I'm missing out on other combinations of compound and pads. What works best for you? (Im using a flex, dewalt polisher, porter/cable and purple meguires pads, and random finishing pads)