This is a two-fer, maybe even a three-fer! What sounds like a great book, a great art project, and a great way to reinforce the literacy of the great book through a great art project. What more could you want!
Obviously, this method of making window stickers can be applied to any graphics that your child might choose.
But why not encourage graphics related to a favorite story to encourage the literacy? And why not give what sounds like a good story a go at your house?