PlastX works pretty good on most/all plastics, if it doesn't work then there's probably not anything that will work.
PlastX uses a special diminishing abrasive, unique to the PlastX product if I remember correctly from my time at Meguiars.
Most anything abrasive will remove dull, hazy, scratched plastic, the trick is doing it in a way that leaves the plastic clear and defect free in the process. Much the same idea of working on modern clear coat paints and most any quality compound or polish that will work on clear coat paints will usually work on plastics.
I believe PlastX also leaves behind some type of protective coating at the same time, kind of like a cleaner/wax, it's able to correct, polish and protect in one-step and that's usually what the average Joe Consumer is looking for.
If the PlastX doesn't finish out perfectly on your plastic, try going back over the plastic with a polishing pad and a fine finishing polish for paint.
