It's pretty good mate, but can take a bit of getting used to using it. If you going over the black, with blue, I'd make sure the prep was perfect and use a good primmer, I'd even consider using their own. And between coats of primmer give a light sand with fine wet and dry. When it comes to the Plastidip very very thin coats, and don't sand in-between, it will just strip off the paint. If you just take your time it should work out well, it just takes patience, and good prep, you can't go wrong then.