I would NOT use Mequiar's Quik Detailer (red bottle) on a Zainoed surface. The Quik Detailer is NOT considered "body shop safe". Therefore, it may have some silicones in it that may inhibit the bonding of further coats of the "Z". On the other hand, the Z6 has some "Z" in it, and promotes bonding of additional coats of "Z".
Just my 2 cents though. :dunno