Polishing tail light lens?

All I know is when I bought my Shelby/Cougar taillights, the lenses were not being reproduced, and the bast I could find was a set of dingy lenses with overspray on them. By using Mother's mag polish and 15 minutes of my time, I had one of them looking like a brand-new lens. I had originally bought some Novus plastic polish, since I'd used it before with some success, but even it didn't do nearly as good a job as the Mother's.
 
if you treat it like paint (wet sand and polish ) it works great. i do this alot for headlights, for example my old mans toyota headlights looked like diffuser lenses. it wetsanded with 1500grit sandpaper till it stopped coming out yellow and turned white, then machine polished with meguires #9, and they looked close to new when done.(ps dont let the polishing compound go dry keep it wet and cool)