I have no experience with Zero, Splash, Gravity, MCW, etc paints, so can't offer specific advice on application. However, the photo seems to show crazing of the plastic. This seems especially visible on the area forward of the bonnet. This occurs when the solvents in the paint physically attack the plastic. Some paint solvents are particularly 'hot', especially lacquers not specifically formulated for styrene plastic (though I have no idea if Zero is lacquer). Additionally, some plastic formulations are particularly susceptible to this reaction. It will be interesting to see if the body soaking in Purple Power shows a grainy surface once the paint has been stripped. You may have to do some priming & sanding with a filler/primer to sort the damage to the plastic.
To prevent this, a barrier is needed between the paint and plastic. A number of products have been used to do this. Most builders ensure a good primer base, and apply the paint in light coats to reduce its potential to attack the plastic. I have heard of BIN and Future being used as barriers, but have no experience with them myself.