I noticed you do graphics, how well do they stick to paint??
Vinyl material, which is used for graphics and lettering, is applied to painted surfaces all the time.
Painted cars, trucks, boats, trailers even window glass!
Vinyl is also applied to gel-coat finishes.
I use the same vinyl for model graphics. No secrete about that!
Just visit my RCU Gallery. There's plenty of models that sport my graphics. All applied by the builder.
Such talent they have!