Car Smileys or Frownies

You know how they first came out with mood rings and then moved on to digital AIM smiley faces? Well, now they have advanced to the point of Driving LED Emoticons to share your emotions with the rest of world according to ThinkGeek. You can stick a lovely glowing representation of your mood in the back window of your car. Now every driver can know to ride on the brakes for awhile when behind a frowny face car. I love the disclaimer, "May not be legal in all states. Check your local laws before use." Do people really buy stuff like this? And what would you do if the emoticon changed in the middle of road? Was it something I did?