Hello, I am looking into an RT Limited. I am curious as to hose the Bluetooth works. I understand the Garmin GPS is Bluetooth and you can use that to place calls from your phone and listen to your radio. Do you still need something like a Scala system for your helmet? How do you communicate bike to bike? Rider to Rider? With so many Bluetooth devices, which is the one ring to rule them all? Thanks. Just trying to understand how this puzzle goes together.