Sense 3.0 (on my Amaze) has Car Mode, I can activate it with Llama from shortcut, or from condition = connect to HandsFreeLink (car's Bluetooth "headset" unit). But I haven't found any built-in alternate home screen. Rather, when I install corresponding car speed/nav programs, they "take over" from the Home Screen.
So clearly (thanks for posting that PocketNow video, btw) they've finished the work-in-progress of Car Mode.