Yes, you need a carseat for your baby according to the law. If he's over 1 years old, you can have a toddle seat facing front. If he's under 1, you need a rear-facing carseat. Most of the car rental company can provide carseat if you reserve it in advance with extra fee. However, some of the car rental companies may miss your order, particularly during peak season. Therefore, if you can bring your own (which can be used in the plane too), it is perfect. Otherwise, you have to make sure that you rent the carseat with the car.
花旗太太生活在花旗國,留意時差,你問我未必即時答到。