I currently have a 6s but want to upgrade to an XR but one thing has me concerned. One of my vehicles has an aftermarket GPS head unit with bluetooth but does not have a steering wheel button to activate hands free calling. With my 6s I can just grab the phone, unlock with touch ID, then hold the home button down to activate hands free voice commands, all without taking my eyes off the road or other hand off the wheel. How can we do similar with an XR? I don't want to have to take sunglasses off and look at the phone to open it... too distracting. Entering a PIN is even worse. Is there a way to just hold a button down to activate hands free calling without opening the phone?