Very fine scratch removal?
Click linky----> http://www.autopia-carcare.com/how-to.html
There are some great write ups there and also on this site by chub*(&^#(&$ (something like that) https://ls1tech.com/forums/appearance-detailing/263061-porter-cable-dual-action-polisher-faq.html
Also, the polish you use makes probably the single biggest difference. There are a lot of great brands...but the polish that people seem to reccommend the most is Manzerna.
Read the writeups on the two links, and look into the 7424...it is a little pricey, but if you plan on owning dark colored cars for a bit...it is a wise investment.
Good luck,
James

http://www.bettercarcare.com/articles.php?articleId=27
worked great for me.

