This is going to come off sounding like a commercial for autopia-carcare.com, but it's where I buy my supplies, so I don't feel too bad...
I use the PCDA with Sonus pads and Sonus polishes (SFX 1, 2 and 3).
Pads:
http://www.autopia-carcare.com/son-daspad-kit.html
SFX-1 Restore:
http://www.autopia-carcare.com/son-410.html
SFX-2 Enhance Swirl Remover:
http://www.autopia-carcare.com/son-420.html
SFX-3 Final Finish Polish:
http://www.autopia-carcare.com/son-430.html
You should always assess the condition of your paintwork before starting and use the least abrasive product that will do the job. If you only have a few swirl marks, starting with 2 is fine. If you have oxidation or excessive swirls, you might be better off starting with SFX 1.
Whatever you choose to start with, you must always work your way to the end of the product line for best results. If you use SFX 1 to start, you then need to use SFX 2 and then SFX 3 before waxing or sealing. If you use SFX-2 and still see scratches or swirls, maybe you should back up, try SFX-1 and then do 2 and 3. If you did SFX 2 and the finish is not as reflective as you hoped, it's probably because you need to do SFX 3 to finish the process.
Think of these compounds as being sand paper. You can't use 60 grit sandpaper (very course) and then apply the varnish! The coarse stuff is to smooth out the big scratches but, in the process of doing so, you create a bunch of medium sized scratches. You then pull out the medium grade paper, not to remove the big scratches but to remove the medium scratches that the course paper created. You keep going to progressively finer and finer grades of paper, repairing the dammage that the previous step caused until your finish is smooth and shiny.
