car rental in St. Lucia

Going to Windjammer July 29. Should we rent a car for the week or just a few days? Is it best to rent at the airport or at the Windjammer? We arrive at SLU but have to use the other airport for departure. Any and all suggestions are welcome. This is our first time in St. Lucia. We love the beach and low cost beach bars. We're very low maintenance but still want to see the island since we've never been there.

We always use Cool Breeze. You can rent at one airport and return to another. I have found their rates the lowest the last 10 yrs running. They will give you a free day/ week.
They also have a kiosk in Rodney bay which is near WJ and will deliver.
If you are the kind of people who like to do your own thing, break away from the herd, then you may like renting a car for the week. If you're nervous with directions, like to join tours, then maybe just a few days.
We probably only eat at the resort one night a week but we do eat lunch there when not out and about. Rodney Bay has tons of restaurants, and of course there is Laurels for super cheap, amazing lobster, just down the road.