I see looking at your instrument panel readings or making adjustments to your radio system just as distracting. What is one more piece of information than something that tells where you are?
Any phone call can be very distracting. A hand-held cell phone call is very distracting, while driving. Glancing at your instrument panel, or adjusting the radio are (usually) less distracting. They don’t require much of your attention.
I find that my window-mounted GPS isn’t distracting, when it’s in voice mode. Sometimes, it removes distractions — e.g. you don’t need to look at every street sign, or building address, when you’re traveling to an unfamiliar destination. You can focus on road and traffic conditions, rather than navigating.