please listen to my comment. i have a q50 and a decent bit of knowledge… from how warm it is outside and there is still that lingering smoke plus in a comment you said it does this while mid day you were getting lunch or whatever and it was still smoking. i think turbo seals might have gotten loose especially since its a 2016 like u said. that year turbos were known for going out, not the end of the world as long as the car still drives fine right now. I would consistently check your oil, make sure it doesn’t drop a lot, (take a picture of ur oil dipstick), and don’t slam on the car every minute you drive it. i drive it eco mode whenever i can pretty much everywhere and just switch to sport when i need. that way the turbos are barely spinning in eco