Okay here goes:
Wax won't do a thing for plastic.
I assume that by hazing you mean oxidation (frosted glass look with yellowing).
Start by removing oxidized plastic. Based on how bad/deep the oxidation goes, you have to pick a removal method.
From most to least aggressive (IMHO)- Wet/dry sanding, compound (car or plastic) with rotary pad (on drill), plastic cleaner (I like 3M), plastic polish (again 3M).
Finish with 303 aerospace protectant. 303 contains UV protectant (the only one to my knowledge) which will slow reoxidation.
Be forwarned. Sometimes the oxidation extends through the entire thickness of the plastic. At that point you have no choice but to replace it.
Good luck!
