On Sunday, July 16, 2017 at 8:11:30 PM UTC-4, Danny D. wrote:
Overall, do those yellowed polycarbonate headlight deoxidizing chemicals or
1600-grit polishing solutions actually work well enough to be
indistinguishable from new?

Why is that the standard? I haven't seen anyone claiming that they
will restore them to be indistinguishable from new. I used a kit,
I think it was 3M, worked great. It included an attachment for
a drill with pads. There was a huge improvement,
I was very happy, but no way I'd say they were indistinguishable from
new. It lasts several years, but obviously the process continues.
Same thing will happen with new ones. The choice is up to you, but
I'm sure you're not going to find new ones for $10 which is about
the cost of the polishing kit. And the lenses were poly or similar,
not glass (does anyone still use that?), so the part about it not
working on anything but glass is BS.