2 Qs: Black Painted Roofs and "Track Package"

Question #1: Is there any significance behind the roofs of some of our GT350s having solid black pain as an option? At ~$650 no less. I would have rather had the extra money but the black roof and mirrors looks great on my color (magnetic).

Question #2: Forgive my ignorance but I have been watching loads of YouTube videos on our machines and so many mention "track package." Was this an option on the 2015-16 models only and came standard on `17+ models? What's the difference? Just the addition of coolers for the transmission, oil, diff, etc?

Thanks!