When we were planning last year my awesome grandson was going to be with us. I inquired about the law on child seats and was told there isn't one. We still used one that More4Less provided at no charge. It was clean and in good sahpe. Also this from years ago: Kid car seat
Not sure about the law - seems like it might not be, but I'm not that comfortable going without one. For light packing purposes we have a Ridesafer travel vest for my 4yo that turns a seatbelt into a 5 point harness and an inflatable booster (bubble bum) for my tiny 7 yo. Figured the booster will be our extra one after the trip for carpooling here and borrowed the ridesafer from someone who had just travelled internationally with 2 little ones. Both will fold pretty flat and then I'm not worried about the condition of someone else's seat. GL!
I contacted Ricky/Anky of Wheels2Go rental car if there was a law regarding car seats. Since they have a 4 year old I thought they would know if a car seat was required. But they said they would look into it and get back to me. They do have car seats at no charge if you rent from Wheels2GoAruba.com. More4Less also does not charge for car seats.
I would strongly suggest you use one not mater what the law here is. Most drivers here are as careful as in the states and for the one time you don't use it, that will be when something happens. . . I do believe that most car rental places will let use one free of charge. . .
I when to the police department concerned with traffic today because I was getting no where on the phone. The told me they have no written law to give me but an officer took his time to explain it to me.
The law is very simple: passengers in the front seat of a car need to be 12 years or older, and must be wearing a seat belt at all times. Passengers that are younger than 12 must be in the back seat of the car. There is no law that stipulates that the passengers in the back seat must be in a child seat, booster seat or wearing a seat belt, no matter the age, but they recommend child seats, booster seats and wearing a seat belts and encourage people to do so.
We also encourage our guests to use the seat belts and we have child seats and booster seats available at no extra cost.
I hope this was of some help answering your question.