Someone on the internet used to sell these bumper stickers.
I checked his site a couple of months ago and he was out of business.
Too bad. I wanted to buy 100 for our Tea Party group.
You can still get them: https://www.google.com/search?q=coexist+bumper+sticker+gun+manufacturers&aq=0&oq=coexist+bumper+sticker+guns&aqs=chrome.1.57j0l2.15889j0&sourceid=chrome&ie=UTF-8