There is an Indiegogo projects that may address this topic: AppYourCar

I am using Waze on a Samsung Galaxy 3 with a Blueant headset. I love your remote control idea. I can hear the voice narration while I am driving but I'd love nothing else but for it to be in listen mode so I could give commands on the fly. A remote control type option would be sweet. I used to use VZ Navigator (saved myself $10 a month). Switched to Google Maps but their traffic and community is non-existent. I love Waze! I vote for a remote control option as well.

The newly announced CarPlay technology (Apple) may bring some enhancements to the way in which we interact with our phones in the car.
However, from what I read so far, CarPlay relies on the touch screen interface of the car manufacturer's proprietary info-system (embedded into the dash board).
Although this is a convenient input device (as you can define all sorts of buttons on a touch-screen), it's not the best way to interact with your technology while you're driving. Not only you will spend more time looking away from the road to your touch-screen but you will also take your hand off the steering, reaching to the middle of the dash board, swiping and touching icons on a screen.
In my view, the input should be done via a remote control mounted on the steering wheal. A sort of mouse for the car.
It would work great with Waze - reporting traffic events, liking/confirming alerts, etc - directly from your steering wheel. It's safer and more comfortable for the driver (you will keep both your hands on the steering wheel at all times).