I have never fished there myself, I really only go down that way to target Moki. To the best of my knowledge the only place where one car park cars is right in the middle of the bay. Alternatively, one could park where the Surfies park and walk from there.
If my memory serves correctly last autumn a guy who I have meet down there several times before mentioned he have seen a dozen or so snapper caught of the beach at Mangamaunu… over the last summer or so.
The asian guy with all the cool gear caught one of the old wharf last autumn, went about 7lb or 7kg from memory.