I bought Z-1 and Z-2 Pro. The first application took less than an hour to dry in the sun. I don't think you really need ZFX, but it's probably nicer to have, especially when it's not so hot out. If you live somewhere warm though, I can't really think of a reason why you would need it unless you're just ... how you say ... lazy. Or impatient. Or maybe if you don't have all weekend to spend on your car like I usually do. Hm. Maybe I should buy some.
