I've had this on my car for about a month and got the idea right here at 911Blogger. I keep a supply of 911 Mysteries in the car to hand out anytime someone asks about it or looks curiously at the sign. If you're interested, I had this done up at a local Fast Signs for about $65 and, yes, I gave them a DVD when I ordered the sign.
We're winning people. These murderous traitors will be on trial soon.