Just remove your dome light housing by carefully pulling down from the rear and you can see/hear where the noise is coming from when you push up on the headliner. I threw a thin mouse pad between the roof and headliner and noise is gone. Just keep pushing up on the headliner and adding electrical tape to the corners of the objects that rub.
There is no need to pull down the entire headliner, you will cause more future noises than you will cure...

 

True....but the dealer did pull the headliner down as evidenced by the finger smudges by the sunroof controls. It's under warranty, so I hope not to have the squeaks return. This was a problem from the first few weeks of my purchase.