Send all sound through Lightning cable for full hands-free capability?

I recently purchased a Mazda CX-5 and don't have Bluetooth capability (cost did not justify). The car has USB port and works great for playing music and using Maps for directions and routing those sounds through the car speakers with my iPhone 5.

The problem I have is when using Facetime...

Let me explain why I use Facetime before I get blasted from everyone; my partner is stationed in Japan. We communicate through Facetime, iMessage, and email as international calls are costly. Due to the time difference, the only times either can call is during my commute to my base. I do not need the camera ability, so essentially I want to use Facetime as a handsfree phone call. When I do this, the sound is not routed through to the car speakers but default to the phone speakers.

Is there a setting I am missing? I have searched through Mazda specifically, but to no avail.

Thanks!