My 96 Grand Caravan had yellowed lenses that were such a PlTA to polish
(wet or dry) that I opted to buy new AM headlamps on eBay.
The headlamp covers on the modern Hyundais are Lexan (I have keen told) and
that is supposed to be pretty tough but not necessarily hard. So if they
somehow got clouded bringing them back will not be easy. Wet sanding as you
described is probably the best bet to get clarity and sheen.
Wet sanding will require buffing afterwards though Wayne. It will leave
scratches that will not give you the clarity and sheen. I'd stick with
just the rubbing compound, but if the going is slow, use a good buffer. The
kind a body shop uses, not the kind most folks might have for buffing their
hardwood floors, etc. Those can actually work ok for polishing the finish
on a car, but for taking down scratches, etc. you really want a higher
speed, more robust buffer. The caution with those is that they can burn
through paint in a heartbeat, so the user has to be careful when using them.
Don't let the bonnet touch the surrounding clearcoat. You'd be surprised at
how quickly those things will take an edge right down to bare metal. That's
why I originally suggest lots of elbow grease to the OP.
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