I was in Sint Maarten/Saint Martin two months ago... I used both terms because in the short time I was there I stayed on both the Dutch and the French sides.
I rented a car from Thirfty who share the facility with Dollar. I got the cheapest vehicle available at that time, which was a Hyundai Getz, but they also had very reasonable deals on Jeeps. The car rental places are offsite and the shuttles go frequently, but as everything else at SXM people take their sweet time and nobody is in the rush.
While doing research for the car rental it was possible to rent from no-name local companies that offered decent deals, but for me their terms didn't sit well, plus a global chain seemed safer and I was able to decline the insurance on my car.
The car itself, the Getz, was fairly beat up on the outside with several dings and scratches which were checked off by the person on my contract because I declined additional insurance. I drove around the island a lot and basically circled the entire thing once or twice. The roads are fine and I wouldn't worry too much about additional insurance especially for the Jeep... however if you start exploring beaches and start taking the vehicle offroad just be careful... however its nothing like offroading on Aruba where you could lose a wheel going to the Natural Pool.
I stayed at the Sonesta Maho Beach and L'Hoste at Orient Beach, both places offered car rentals from their lobbies which would be delivered to your hotel. The airport is probably more convenient though.
Driving around Phillipsburg was fun... none of the maps I got were accurate and due to a lack of street signs you might need to give yourself a little time to find a specific spot you're looking for. This was particularly the case for me finding Dock Maarten when taking a day trip snorkeling in Anguilla.
The restaurants on the French side do still offer 1:1 but they were primarily fast food... decent places were 1.40:1 or 1.50:1
I highly recommend Big Fish restaurant at Oyster Bay which is right on the French/Dutch border which did offer 1:1 and it was absolutely delicious.
Enjoy SXM!
--Russ