Just did some more searching and I see that some people recommend several drain and fills and running the heat on high. I'm assuming the heater is just run between fills?

 

Yeah +1 on that!

 

one drain & fill after 4yrs/60k miles is fine - no need to flush. Make sure to replace the coolant every 2yrs or 30k miles thereafter.

 

The owner manual indicated just drain and fill. Make sure that you drain into a container, not just for environmental reason, so you know how much to put back into the radiator. If you use the new Preston coolant, it's probably good for the life of the car. Remember, the main reason for changing the coolant is to put the additives back into the system. As for the antifreeze protection, the old coolant does the job as the antifreeze property will not break down.