Dollar.UK定好的车，追加一名驾驶员需要增加费用

我看坛子上的各位大佬游记里都说是要增加10USD/天，但是Dollar客服给说跟对方确认过是免费的，到底需要更改为白金服务吗，我在踌躇中
Please note the additional driver is free of charge in this location, which I confirmed with the car rental