Every time I shut my '15 off I have the coolant smell as well. No leaks that I can find, but the smell is there. All my heat works fine, but I just have 18Kmiles. Should we be flushing our cooling systems to avoid any of this?
IMO if your smelling coolant there most likely is a small leak somewhere most likely the radiator.
My 2014 and two other friends with 14s have had the smell every time it was shut off. Never a drop on the garage floor.
Drove me a bit nuts for a while looking for the source but did finally find a very small leak about 4" down from the top of the drivers side radiator.
Dealer changed it out for a new one on my jeep and also one of my friends. Other just had his in and the dealer pressure tested it and said it's fine.... not.
His smells the worst of the three lol.
Anyway I have plenty of heating/cooling so as of right now lifes good