Re: Sound in navigation problem
Hmm this could be a tricky one and might be an issue with the phone or more the Bluetooth car kit itself. I don't have the G3 myself yet so can't test this but have come across the exact same issue previously with several phones. The last time this happened the issue was down to the bluetooth car kit and its firmware and how that worked with the navigation software.
In Android phones in the bluetooth settings area you should have a list of paired devices, one of which will be your BT car kit. Next to it could be a settings icon to access the next menu, sometimes a long press is needed. In there is the BT profile setting, make sure that both phone audio and media audio is enabled if available. I can't be more specific as I haven't the G3 but that is how it is on other android phones.
Then you're going to have to go through every level of setting on your car kit in fine detail along with the instructions to check if there is a setting available to enable BT audio from media/navigation. I have the Bury 9068 and did all this and it still didn't work. The issue was that the kit mutes the phone as standard when connecting BT but it was not accepting the audio from the Nav software. In the end after contacting Bury they updated their firmware and after updating my unit the Nav audio then worked properly.
Hope this info helps you get to the bottom of it and find the issue with your particular combination of phone and kit.
EDIT
Also you should check as to whether your car kit supports the LG G3 A2DP protocol used in the phone. I just checked on the Bury site and it doesn't support A2DP on the G3 while it does on nearly every other modern smart phone. Not sure as to why as yet, if its something about the way the G3 uses A2DP but thats something you may need to look at also,