Think of it like a mini-scoreboard on the back of a car. You can use it to (a) display messages to tailgaters to back off, (b) speed in front of a hot babe and ask her out, (c) politely ask if someone would let you into line, (d) share jokes and political comments, (e) share sports scores (Eagles win! Eagles win!) (f) sell ads! Of course, the pitfalls are perilous: Ticking off the road-rage-apoids and distracting drivers into having accidents. Posting messages such as “I’m armed and loaded” might deter — or incite. Even wilder idea for abating tailgating: The remote-control truck lid that opens up, revealing a slowly raising phony machine gun that pops out a flag with Yosemite Sam and the words, “Back off!”