When my boys were younger, we used to take road trips to see their grandparents, who live eight hours away. One of their favorite things was to stop at the Turnpike rest stops and buy those small toys and trinkets from the vending machines. We turned that into a behavior incentive! As the boys displayed good car behavior, we would dole out a quarter for them to pop in their pockets. They loved EARNING change for the little goodies that in turn kept them happy and entertained in the car for the next hour!