did i ask the shout out louds for permission for what? not quite sure what you're refering to... the lyrics?
as for the clip art thing... i would probably have to agree that they have a cheap clip art quality, partially due to the little dots that showed up when i saved it as a gif... the dots aren't supposed to be there. I can assure you that they are not clip art though... they are made out of the shapes on the grillcloth of the radio
Yes, the lyrics, bobbyleonard. You're taking an artistic work (song lyrics) by the Shout Out Louds and incorporated it into another artwork that will be sold for money. That's distinctly different from someone posting the lyrics on a publicly accessible website of song lyrics, and could be a violation of their copyright. At the same time, there's no credit given to the actual creators of the lyrics, so someone could get the impression that it was something written by you. I don't know the specific legality of it all, but I'd recommend a) asking them for permission, and b) including something somewhere on the shirt that makes it clear that it's something written by the songwriter(s).