Garmin Navigon/HUD with WP help

[rybob1]

Looking at purchasing the Garmin Head Up Display, that is supposed to work with their Navigon App on Windows Phone. I'm curious if anyone here has one, and what their impressions are of the way it works with WP. Specifically, I'm curious how, if possible, I can have a Bluetooth connection to the Garmin accessory, while also play music/audio book from my phone via car radio.