Decals won't adhere to a flat finish, they need a smooth, glossy surface to stick well. Therefore you need to spray the red first, then lay down a gloss coat before applying decals. Some folks then put another coat of clear over the decals to seal them but I never have. If you decide to, test first to make sure the clear your using is compatible with the decals. Just a thought, you may want to tackle something a little simpler than the #24 for practice. That is not an easy scheme to complete, FWIW.