Would using Meguiars Plastx remove the original UV coating?
In my experience, PlastX can be very effective in some cases, yet pretty mild in abrading ability. We just went after my brothers headlights on his 2008 4Runner. They were just beginning to get foggy on the top edge and slightly swirly on the fronts like the OP's. My bro had the same fear as the OP- didn't want to compromise the OEM UV coating.
We scrubbed by hand pretty hard with PlastX and terry cloth, and barely put a dent in the cloudiness on the top edge, although it is somewhat improved. I attribute the improvement primarily to polishing oils.
We then used a Megs yellow foam pad and very lightly buffed the front of the lenses and also saw a slight improvement.
All said and done, I really doubt we took off much of the UV coating. And if we did take some off, it was likely the oxidized bits of "failure". My thoughts on this are that you're better off removing a little "failure" and having a smooth surface which you can then keep sealed. As opposed to having an oxidized surface that accumulates grime in the recesses and continue to oxidize.
It is what it is. Choose a direction and run
I'm not sure there's a "best" answer. But there are ways to improve the appearance.
As far as "least aggressive method" goes, I think the OP would probably be happy simply hitting it with something like Megs headlight protectant.
But PlastX also has a sealing component to it, and one can get very aggressive or simply wipe it on and wipe off-- That certainly wouldn't compromise any UV coating. Or you can go anywhere in between as far as buffing goes. You can basically go ZERO to 60 with it. Use a DA and you can go 90.
