Has anyone figured out a way to use "OK Google" without tapping the screen?   I tried using a Satechi BT Home button ( http://www.amazon.com/dp/B00RM75NOW/)   with a Bluetooth remapping app on my phone. It works with my phone not connected, but once I connect my phone to my headunit, the phone doesn't respond to the BT button.    

I don't have steering wheel controls, and I am just trying to make it easier to use voice command without taking my eyes off the road to look for and tap the onscreen Mic button.

Thanks!  

I think you have to access the "voice" function through steering wheel control remote jack.

I realize you do not have steering wheel controls (assuming you mean no OEM controls).  I added a PAC WRI-P Wireless Remote Control Adapter and a Pioneer CD-SR11 to have steering wheel controls... but I'm not a "connected in that way" kind of guy, so I don't know if it works with "OK Google" or not.

Do what I did... build one of these (I think the total cost was about 5 bucks).

http://avic411.com/index.php?/topic/81233-i-now-have-steering-wheel-buttons/&do=findComment&comment=332877