I used to use the Zymol and liked it, but that was before I got the PC. Autopia is a great site with loads of useful information. I am getting set for my spring detail on my Jet Black X. I use Klasse AIO for wax/sealant. Here is my process:
Wash with Dawn
Clay bar
Intense polish
Polish
Wax
Here is a pic of the ride I had when I got the PC. It had swirl marks but I was able to get the polish looking like this.
The polish I used for this detail was Einzett (green can) which Autopia stopped carrying. I have tried the Sonus line with my X, but did not acheive these type of results. I am going to try a more aggressive polish and pad as mine has ridiculous swirl marks. The damn swirl marks almost makes a case for buying brand new, if it weren't for the whole depreciation thing.