I'm wondering if this problem I'm having has to do with my navigation/BT system or maybe just a design of the phone...when the device is paired with my nav system the phone doesnt let me adjust the volume. Is this normal? All my other phones I've ever had allowed me to adjust the volume..
My Parrot car kit system lets me use the phone volume...check manufacturer website of GPS to see if there's an update. If not, send them an email to see if there's a fix.