I got a new passport and learned you can get any image you want printed onto a passport holder, and this had to happen.
I briefly considered making some original cover art based on how the Guide itself is described in the story, but I then thought about all the reasons not to pull out something that says "DON'T PANIC" in large, friendly letters in view of some jittery border guard who may not get the literary reference.
It's fine to have it says "don't panic" because it would be written in friendly letters