dont use metal polish for the lens, those will dry up the lens further. use the Meguire plastic polish to do the job.
If your lights are the old style non angel eyes lights, you may replace them as the lens are detachable from the case. for the hella angel eyes lights, too bad you cant even open them. technically you can, but its hell of a lot of effort. the only option for you would be to do the following:-
you may send the lights to any automotive spray painter, they can polish the the lens to a very good condition if the lens is not in very bad state, any superficial scratches or haze can be polished off with a good polishing compound they have. spray a clear coat over the lens and it should be good for another few years. the clear coat will prevent any further scatches and UV damage to the plastic layer. DONT be CHEAP and used those spray bottle clear paint. those are not UV proof.
there is a few guys in sunway and kayu ara that is known to do this. charges will be around rm60 per light.
here is a good tip.... just send your car to the painter for a full body polishing and compounding, most used car dealer use their service as a cheap auto detailing to freshen up old cars. the standard rate should be around rm200 for the service. just ask them to polish all the lights, front and back in situ, its normally a no charged if you buddy up with the guy doing it. then for a small 20bucks top-up or nothing at all, just ask the guy to clear coat the lens as well.
