I've been learning all this myself.
Apple Carplay is suppose to project the items from your phone onto your screen when the device it plugged in. However, that only works with a few 'compatible' apps. From what I'm learning (but I could be wrong) - is if you plug in your device, the compatible apps will show up on your carplay screen. Which....I see the Apple video player is in there. ?? Curious....something else to experiment with!
http://www.apple.com/ios/carplay/