Invented by Mika Larson, who sells them from her website named — surprise! — roadrage.com. You get a spiral-bound book of 8- by 11-inch cards, each with one of 43 messages, for $19.99. But here's the stroke of genius: on the back of each card is the mirror-image of the message so the doofus ahead of you can read it in their rearview mirror.

[via Joe Sharkey's "On The Road" column in the May 23 New York Times]

Posted originally at bookofjoe: Road Rage Cards: 'Relax %u2014 and let the flip-book do the screaming!' and republished here by the author