Dominican Republic offer a lot of car rent companies. You can rent your car directly ad the airports of the Dominican Republic.
We recommended to rent a car at least a mid size type car in the Dominican Republic. The engine power of the economy and compact rent a car types is often insufficient. When you are driving in the in the mountains with the aircon switched on, the engine can hardly provide the power you need. Larger cars often have power brakes, power steering and air bags, which make them saver. You will probably be driving over large distances and a decent car really pays off then.
Method of payment for a rent a car in the Dominican Republic. Most car rental companies require that you have a credit card for payment. Your credit card is also used as a deposit.
When you are stopped by a police officer then your drivers licence and the car registration is required. Since you don't have a car registration, you should show him your rental agreement.
Before you drive off , check the your rental car for any damages. If you find any damage or scratches on the rent a car, report this to an employee and he will make a note of it on your rental agreement. If you don't report any damages, then they may charge you for that damage after returning the car.
Only the person who rents the car is allowed to drive it. If somebody else besides you will be driving the rental car you must mention this during check-in. An additional fee may be charged for a second driver.
Insurance for the Dominican Republic
When you rent a car a basic insurance is often included., this basic insurance is insufficient because it offers only a limited coverage of damage. Also an own risk is often applicable. Because every country has its own legislation, the exact coverage depends on the state where renting/driving. Rental companies will offer additional insurances.
LDW (Loss Damage Waiver) or CDW (Collision Damage Waiver)
A LDW or CDW insurance takes care of your own risc. If for instance your rental car gets stolen or damaged, then the LDW will cover the costs. If you rent a car via a travel agent in your home country, LDW/CDW is often included in the rental fee. I strongly recommend that you take this insurance.
LIS (Liabillity Insurance Supplement)
A LIS is often not included but recommended. LIS covers the costs of any damage or injuries that are a result of an accident you are involved in. A LIS insurance will cost about USD 6-8 per day.
Other types of insurances
Other insurances are PAI (Personal Accident Insurance), UMP (Un- and Under insured Motorist Protection)
Insurance is expensive so check, if you really need to accept any type of insurance. Your rental car may be covered by your car insurance, your travel insurance or any other insurance you have already. Also credit card company sometimes include a rental car insurance, if you pay with that credit card.
Anyway you should make sure that you are not under insured. Otherwise If you are involved in an accident you might end up paying for any damage.