2004 H2 Pics (Nav Screens, Antenna, Wheel, Cup Holders)

[NJ H2]

While using the NAV and listening to the radio, will the radio volume lower itself when the NAV voice come on to tell you your next turn?
Also, do you happen to know what kind of multi cd changer could be plugged in to the inputs on the back of the DVD NAV Radio and if so can CD's in the Multi CD Changer be controled by the radio controls and can the CD's be listened to while using the NAV?
Lots of ??? sorry!