and QD is a cleaning agent, not of polish content?
Is optional ..If u think your car is clean after wash then u can apply or spray the Aquawax then skip the QD. May I suggest u QD your bonnet to chk whether your car wash was really clean. DG521 QD is a time saver product and make car care easier. It contain some cleaning and some enhancement on look. Some used it as waterless wash esp those staying at condo's or perhaps those ppl tht always on the go. It ease the job of removing birb bombs , dust and other light contamination. Its lubrication will helps to prevent scratching if used with quality mibrofiber towel. QD is not a polish agent.
I normally used Aquawax as topper meaning used it after I hv apply some sealant, of course quite a lot of my user used it as standalone ..depends on your expectation.