In this region, car seat laws differ greatly. While in the Dominican Republic and Cuba it's enough to use seat belts, many mainland countries have clear regulations.
Here is an example. In Barbados, children under 4 must travel in a child car seat in the back seat of a vehicle. Children aged 4 and older — in the back seat using a seat belt. The fine for violating these laws is 500 Barbadian dollars (around €222) or up to 3 months of imprisonment.
In general, the situation in the Caribbean is similar to that in Asia — seat belts are compulsory, but cars don't have them and everyone ignores child car seats. At the same time, serious accidents are not uncommon here.