Unless the renter has a safe, secure, place to lock it up at night--like inside a gated community or inside a garage--one would have to be "Insane" to rent out a car for an extended period of time...especially if the renter has never driven on this island at night, or and has never driven in Santo Domingo, Santiago, or anywhere where the manhole covers have been removed, etc.
I would have to say, for someone to take this chance, they would either A.) need their head examined, B.) are in possession of a beat-up, piece of crap car that barely runs, or C.) are themselves new to the country and don't know any better, or D.) are not from this planet. How else are you going to rent a car to someone you don't know?
How about if the renter hits and kills someone...like the thousands of people driving around at night without lights?