No, you cannot take your rental car from Puerto Rico to other islands like Vieques or Culebra. Rental car companies do not allow their vehicles on ferries to these smaller islands. For example, if you rent a car in San Juan, you won’t be able to take it with you to Vieques. Instead, you’ll need to leave your rental on the main island and rent a separate vehicle to explore those areas once you arrive on Vieques or Culebra. This policy ensures the rental cars stay within the mainland for logistical and insurance reasons.