I've been trying to get my LG G3 to work the same as my Windows Phone..., but I can't find anything out there that does this seamlessly as the Windows Phone does...
Natively, you can hook the phone up to the Bluetooth in the car and receiving calls seems to work fine, but its the Text To Speech side of it all that falls apart with the Android... On the Windows Phone you have full functionality including receiving texts via your cars speakers and replying to texts..
After hours of trying to get something to work all I have found is an app called AGENT, that reads the incoming texts to you.., but that is all.., you can't reply to them..., so I guess its better than nothing, but nothing comes close to the seamless way the Windows Phone work with the Bluetooth on my car...
I find it really odd that this function that we have had for years on Windows Mobile doesn't seem to exist on Android..., once you have had it its very hard not to accept that you no longer have it....
My LG G3 is back in the cupboard until someone works it out...