How Can I Connect My Garmin Gps To My Car Stereo So It Interrupts My Music When It Says A Command?

I want to connect my Garmin Nuvi 360 to my Mazda 6 car stero. I know how to connect it via an FM modulator, but can I make it so it will interrupt what I am listening to in order to state the commands (not over the music)? Any thoughts?