That makes no sense at all. it won't work without the nav disc in the CD drive. Did the dealer think you burned your maps on the CD and THEN used it in the HK stereo? I was a bit disappointed in the HD GPS. I feel at least the contents of the NAV CD should load on the HK unit so the CD player can be used while navigating with the GPS (another draw back). Believe it or not, I like mine enough to keep it. I'll just listen to XM or FM while using the nav function. I'd hate to get lost with a scratched NAV disc though. I hate asking directions.
You can use the GPS while listening to a CD, I do it all the time.
1st ----insert GPS CD, program your route of destination.
2nd ---once trip is planned, remove GPS CD and insert your MP3 CD.
I use MP3 files on a CD to get 250 songs on one CD, it's great!
The music will automatically go off and your GPS will announce an up coming turn, then your music will come back on automatically, you can also adjust the volume on both the music and GPS seperatly. I played with mine (GPS that is) in the driveway and just tried different things.
Me read the manual never, so self respecting man would ever read the manual first.
Maybe after a few Captian and cokes.
Ride on!