I agree, it's about the prep. get everything REALLY clean, and then also use an adhesion promoter - I think SEM sells and recommends this, but I actually just used a mist of thinner in my application (tested it first) just to give the vinyl a bit of tack for the paint to adhere to. If you do the prep then I think there are any number of vinyl paints that will work. AFAIK, there really is no such thing as a vinyl dye to apply (even though some call themselves that) - they are all paints really.