Hi, our approach has to take a cab to our vaca rental and have AAA [or your choice] drop the car the next day at an agreed time. Your choice to either drive the car back or again our approach is to have AAA pick up the car and the next day we cab back to the airport
For a cab we use Wilfred Brooks - after a day of traveling, to SXM, nice to not have to worry about the drive, like to catch up with Wilfred and he'll stop along the way if requested.
Same on the way back, this last winter we did our Rhum & Marigot market shopping on the way back to the airport with Wilfred , that saved us a beach day!

Regardless, enjoy
J&B