Belkin’s new Road RockStar ($40) is a clever new car charger specifically designed with multiple passengers in mind. Road RockStar has a total of four USB charging ports — two ports in the front section, which plugs into a car’s cigarette lighter, and two more ports on a hub at the end of a 6-foot cord. All ports are capable of 2.4A charging speeds, and Road RockStar supports up to 7.2A charging simultaneously (three of the ports at…