Keep in mind that if you have oxidation of an kind no wax or sealant will last very long. You need a good foundation to build on. I am now starting the ritual with the 32' fifth wheel. 2 summers ago I compounded then used DG 652 and 2 coats of DG 601/105. It has what I consider minor oxidation but fiberglass is very hard. I started with DG compound for fiberglass and a moderate wool pad. That process was going very slow and not the results I wanted so I switched to Megs 105, better but still lacking. The final now is the most aggressive wool pad and 3M's heavy duty ( rocks in a bottle ). This is working well. When the fiberglass is looking the way it should I apply DG 501 with a moderate foam pad and a DA. 2 days and I have the worst side cleaned up. 960ish square feet of fiberglass is a lot of buffing. I am going to go over the 501 with 601/105 and considering using 601/111 as the final coat. Before the Duragloss binge I am on I used various other sealants/waxes such as Klasse, Megs, Liquid Glass etc with what I consider dismal results. All of this is just my .02 cents. I have gone over all of my decals with all of the products listed with no ill results.
Dave