I got this for my wife as a gag gift because she is always complaining that she wants to tell other drivers what she things of their driving. I was hoping for something that was a little more user friendly, but it was cute to play with for a while. The biggest problem was the install. The device and remote had to line-up pretty well in the car, and that wasn't too easy. It would also be better if you didn't have to "learn"/remember the signs with multiple button pushes. Honestly, I found that it could be a big distraction for the driver if they were trying to operate it.
I'll probably use this at the house at Halloween to get a laugh out of the kids coming to the door. :)