I don't have the nav either but it works fine for my HTC Desire HD with both Android 2.2 and 2.3. Took some time to set it up thou and im not sure how the heck I made it work. First I managed to connect as phone as you, then I managed to screw that up and only connect as audio. After that I did finally manage to connect to both phone and audio. Its quite messy to set this up without the nav :/
As JCP says; the car does only search for BT-pairing for a little while (like all BT-modules), so you should have BT enabled on the phone before you start the car (with an android you can automate this very smoothly by tasker, for example. I have it so that it enables BT, GPS and maximize the media volume when I place the phone in my dock(charger).
Try to have the car stereo in the BT-mode when you start the car, I think that was the trick to fix my connection the first time but im not sure.
Do also set the car as priority 1 for BT-connections.
And then you should look in the phone so that you have both media and phone functions enabled for the car-bt connection, mine was only phone by default. I dont know what version of android you have but it should only be to long-press the car-audio connection and choose "alternetives".
Ok, not very much direct help there, sorry. I dont know exactly steb by step how to fix this. If you take your car over to sweden ill take a look
Good luck!
/Max