Just picked up a few of these. Thought someone else may find them interesting. I have no affiliation with the shop selling these.
http://www.amazon.com/Zombie-Hunting-Permit-Bumper-Sticker/dp/B005JPNXC8
http://www.amazon.com/Zombie-Hunting-Permit-Bumper-Sticker/dp/B005JPNXC8