Thinking of getting a 2017-2018 G63. I have found a few that have relatively low miles at a decent price point. My questions mainly surround the typical cost of annual maintenance, and what are the typical repairs that will need to be made (as well as associated costs) over the next few years. Any major malfunctions, or "surprises" I should be aware of at certain mileages? Any guidance you could provide would be greatly appreciated!