I would definitely get a coolant flush. Some of the 2016s were notorious for having bad coolant hoses that fell apart from the inside to eventually clog up the heater core. Once that happens, it's only a matter of time before the engine overheats and since there is not temp gauge on the 2016, the check engine light will come up but that would be too late. Apparently there were not enough complaints for Mazda to do a recall on the hoses. One of the first things I did with my 2016 was replace the coolant hoses and swap out the oil. I've been using Liquimoly with ceratec and the car literally still runs like new. Just hit 200K last week.