Wing Roadie
Derived from "wingman", a wing roadie is a driver in a caravan of cars that helps out their fellow caravan drivers by blocking traffic to help them switch lanes, get around slow drivers and stay together.
Jen: "Hey Jess, that was awesome when you cut that guy off to let me in. I would have been waiting forever!"
Jess: "That's what a wing roadie is for, man!"
Jess: "That's what a wing roadie is for, man!"