My wife's 2010 five door grocery getter is four and a half years old with 15,000 on the Odo. Mazda says swap the coolant at 60,000 or four years. Is a coolant swap really necessary considering the low mileage?
You're probably OK at six years. Just my opinion. I've changed the coolant in my older car (2002) only twice and the radiator is still holding up fine. As the previous poster mentioned, not a high priority but you do want to be considering it if you plan to keep the car.