Curious as to what kinda glass coating you have on the car?
I wouldn't top a coating with anything but a complimentary SiO2-type product, many to choose from. When I first started with coatings I topped 'em with everything I could think of...waxes, sealants, wax/polymer-infused quick detailers...they all diminished the self-cleaning abilities of the glass coating itself. Then I got into layering coating-friendly SiO2 products; wash with Gyeon Bathe+, rinse with Gyeon Wetcoat, top with Gyeon Cure. It turns out that sometimes less is indeed more, there was no benefit to all that layering except to increase the revenue of whatever vendor I bought it from.
Regarding the Moonlight, used it on top of WG Uber Ceramic as well as a stand-alone application and while it sure did improve gloss and feel and initially water ran off the car at slow speeds in a most delightful fashion, after a week or so it was prone to leaving dirty/dusty water spots after a rain. Everybody's experience is different, however, so give it a shot...it's an SiO2 product so at least it's complimentary to your coating, may work well for you depending on your climate, maint. habits and car usage patterns.
Since messing around with a large variety of things/combos in the past 18 months, I've become a minimalist and the overall automotive cleanliness experience has significantly improved. We have a glass coating on all of our cars and I now simply foam with Gyeon Foam, wash with Gyeon Bathe and top with a 'sacrificial layer'/coating booster from the same collection as the coating on our cars. The cars stay cleaner for longer periods of time with no intervention from me but your mileage may vary. Like they say...find something that works for you and use it often...everybody's situation is different and there are few universal truths regarding this stuff (LSP's).
Don't overthink it or you'll always be chasing unicorns...I did and never got close to catching one.