A pleasant bluetooth related surprise

I have a 2012 Octavia with the Swing stereo and factory bluetooth integration. I use my iPhone for navigation, using Navigon.

I just noticed today that if I'm listening to the radio instead of something playing off of the phone, the stereo automatically switches over to phone handsfree mode whenever the GPS lady needs to give me directions, and then back again after she's done talking.

And I say handsfree mode because that's what it's using, not stereo bluetooth. This means a lower-quality compressed voice, but I'm not bothered by that because the compression is optimized for speech anyways. In fact, I think my brain finds it easier to process than when she comes in full quality over stereo bluetooth. As a bonus, I also get a separate volume control for the GPS lady because the stereo seems to treat it like an incoming call.