In Sosua try Kobirent
What places in POP and Sosua offer this arrangement?
In Sosua, I rent from Kobirent
KobiRent S.A. - rent a car - Mietwagen in der Dominikanischen Republik
The pages are also in english (upper right corner).
When I am there, I rent from Andrea.
Did rent several times over the years and always everything was fine, great pick up service if needed.
Also solved minor problems like stolen spare tire simple and fair.
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Renting "cheap" from private: can get expensive, because people in need for cash may get the idea that now there is a gringo it is a good time to fix everything with the gringo paying.
If in Sto. Domingo a Hertz car is only USD 10 more than from an unknown company, go with Hertz.
Example: Once had an Avis car from the airport and had a flat tyre. They changed it within 30 min. for free in Puerto Plata. If your car has a problem, a company like Hertz will bring you a replacement wherever you are in the D.R.
Alexander