Zaino can be applied to older, non-clear coated paint (single stage paint), that's what Z3 is for. For clear coated use Z2 (or Z5 if you want to hide some swirls). Its all on their site:
www.zainostore.com
As far as silicone, I can't think of a wax that currently uses silicone off the top of my head, but if you are using Zaino it is best to stick with their products to avoid compatability/bonding issues.