I agree with jeneric21 -- die cut would be THE way to go. Die-cut just means the decal components are separate (like separate letters), but held together with a backing paper on the "good" side (the side meant to be seen). To install, one peels the paper off the "adhesive" side, applies to the surface, then removes the backing paper to expose the "good" side -- done! Might want to think about doing a reverse-adhesive type. That is, adhesive on the "colored" side so that the decal can be mounted on the inside of the window. Go with standard back-adhesive if the intended mounting surface is a bumper or other exterior surface.

JUST DO IT! Great for advertising, and I think the rewards will outweigh the (minimal) cost.

Brian

[other "advertising" ideas to come . . . ]