I have navigation and bluetooth in my car, so I really have no need to "see" my phone's screen at all, and I've been happy with the proverbial little five-dollar "cell cup" you can find in many auto supply stores. This thing:
http://www.amazon.com/Heininger-1073...cUvbUpU4453876
My S6, in its S-View case, fits absolutely perfectly in the middle "cell phone" slot.
My car also has one of those infernal "start buttons," and I just despise driving around with my keys in my pocket, so for anything longer than around-town trips, I put my key fob and keys in the compartment behind the phone. That has worked quite well for my needs.