The Beats icon shows up when I connect to my Toyota stereo via BT. Not certain I can tell the difference, but that could be me more than the stereo.
Yup, just found out it works on my Chrysler 300 as well.
I can switch between Beats on or Off in the notifications and I can definitely here the difference.
Oddly the on-dash button for Next/Previous song will only work when Google Music interface is closed on the phone.
And then it jumps albums, not tracks. Very strange.
The on-board music player that came with the phone will skip to the next track as you would expect.
EDIT...
Figured it out with regard to Google music...
Forward and back buttons skip thru Albums if you were sitting on the Album list, Songs if sitting on the all songs list and Artists if sitting on the artist list. If sitting in a playlist, it will skip songs.
But it only works once you close leave the google music player. If the interface is open bluetooth forward and back buttons don't do much at all.
But Beats does work over bluetooth, so its nice to know that.