Just to chime in here,
If you choose to top the Z with the #16, I would recommend a really thin coating of the #16. It don't take much create a thin coating and thick coatings left on too long can be very difficult to remove.
Here's a tip,
Before using the #16 Paste wax, first liquefy it.
To do this, get yourself a clean, foam wax applicator like the ones Meguiar's sells or come with a lot of off the shelf car waxes.
Place the foam pad into the can of #16 and spin the foam pad briskly in a circle. This will agitate the wax and the agitation with a little friction heat will be enough to liquefy the top layer of the wax in the can and enable it to soak into your foam pad.
Now spread this onto the paint. Then repeat this each time you need more wax.
Mike