When you are painting plastic you have to use a plastic adhesion promter first then primer then base color and clearcoat. I dont think this guy used adhesion promoter and if you dont then the paint doesnt chemically bond to the plastic and there for it will chip and flake right off. When painting plastic prep is KEY. You have to use a good adhesion promoter like bullydog or SEM. For instance ever try and put a sticker on a oilly surface? Well it doesnt work so well. So you gotta do the proper chemicals to get the proper results when prepping plastic