I have a 2018 SHO Performance Pack that I bought brand new. The car at idle, and while driving has a slight fluctuation in the idle. I can feel it and see it on the gauge cluster. I took it to the dealer. They can’t find anything wrong with it. They told me the car needs to break in. Well, 10,000 miles later, it still has this fluctuation. I’m unsure what it can be. No engine light or codes stored. I tuned the car, I changed the plugs fromSP534 to SP542, it has an AirRaid CAI I always run premium fuel.