8110: ATT Navigator and Bluetooth?

I just activated the ATT Navigator on my Pearl 8110 and it seems to work pretty well. The only problem I have is that it is very hard to hear when I am driving. I have searched and this seems to be a common problem, but I haven't seen a specific post with this in regards to ATT Navigator.

I bought the Plantronics Voyager 855 from Radio Shack in hopes it would solve the problem. The lady called someone on the phone and confirmed it would work, but I find it best not to listen to them. Either way, I needed an earpiece so I went for this one. It works well for phone calls, but I can't get the navigation audio over the bluetooth earpiece. Is there an option or setting I need to make the audio go to bluetooth in ATT Navigator, or is not possible to have navigator work with an external audio device?