Your results look quite good. However, with my experience, on the more hazed
headlights than those, you'll really need to resort to sanding. I actually started doing
headlight haze correction before I ever got into detailing, and was told by another experienced person to just go straight to sandpaper.
Headlights are so thick and unlike clear that there is a ton of material there so sanding isn't a big issue.
The other thing is that there are specific plastic sealants made by 3M, and
Wolfgang that will seal the headlight and UV protect it, and not alter the opacity of the lens like the Krylon did.
It's definitely cool to see that you never did them with sandpaper and still got great results though. Good work!