We saw this car on the highway yesterday with a scrolling LED text bar built into the license-plate frame. Apparently it's this "License Plate Flash Frame", with programmable messages for the person behind you. This one was advertising to get recruits for the PA Air National Guard, which operates at the nearby base in Willow Grove.

I guess I missed my chance to wow the world with the communication system I was talking about back in 2003 and 2004.