Let me add a few thoughts regarding this. I just got in from getting after it on my trunk of my '01 Audi A6. I never really noticed the swirls and light scratches on it until today when I was washing it. It was an overcast day earlier this afternoon in St. Louis, but the sun was kinda poking through. I noticed all this crap on the trunk area and rest of car. I have to attempt to do some correction on the hood of a '07 Caddy STS tomorrow morning, and wanted to try a few things out with the 4"ers. I use the Edge 2k system with my PC, and started out with a 6" green pad and Menzerna IP. The swirls/scratches laughed at that combination. It was on speed 6. Next up was Edge orange 4" light cut pad with IP. Same result with PC on speed 6. Alright, I'm all for trying from least aggressive to most, and I'm sure there was a step or 2 in there that I could've tried. Well, sometimes you just gotta go full bore, and my patience was running out. So, on goes the yellow cut 4" pad with Menzerna Power Gloss compound.
Let me say that I got after it. I wasn't screwing around at this point. The nice thing about having a 7 year old car is that sometimes you really don't care. My A6 is kind of a gold/champagne color, so swirls/scratches are kind of hard to see. I have some pretty good lighting in my garage. I did my first 1.5' x 1.5' section on the trunk. I did the usual cross hatch pattern that all the videos show you, and added a few others that I saw on one video on the web where you work it in a litt more by going back and forth while moving along. Also, I was applying pretty good pressure and was covering about 1" / 1 second if that. The pad didn't bog down, but it definitely slowed down. Then, I would make a couple more passes with very light pressure allowing the pad to do more rotation. Then, back to some more a$$-kickin'. I would work a section for probably 3-5 minutes.I did have some success. The sections that were done on the trunk did look noticeably better than the sections that were not. When I do the rest of the care I'll have to take some pics.
In summary, I think it is key to remember that you can't get them all. My personal opinion is that you can get about 75% of the crap off your paint using a PC. Also, like others have stated, you would have to leave that thing in the same spot for a considerable amount of time. Unless you have real soft paint, then you should be fine getting after it with the PC like this. That's my personal opinion. I think Audis are known for having pretty hard paint. I didn't see any negative effects from the Power Gloss and my technique at all. Use this advice as you see fit and remember, it's just my opinion...
But seriously, yeah, it's a great resource all right.