Q: iphone 5c car bluetooth phone only (intentionally)

In my 2012 Prius I go to the Settings in the car, Bluetooth, tap on the iPhone, and there I can choose what features of Bluetooth I want to use. I don't know if the 2013 is the same, but I suspect it is.

It would appear that Apple is lagging a good 5 years behind other phone platforms.

then it's impressive / odd they converted you

It seems this is fairly recent.  I've been iPhone now for almost 4 years.  I've consistently used maps and Bluetooth.  Only recently (past few months) did it suddenly start routing ALL audio to Bluetooth.  I've had the same Bluetooth headset for over a year and when I was driving and using maps, the map audio would come through iPhone, while calls audio would go to my Bluetooth.

all devices I have ever in my life connected with a Bluetooth headset using the a2dp Bluetooth profiles have routered ALL!!!! audio to the headset

this goes for ios devices this goes for osx devices this goes for windows both xp, 8, 8.1, 10 and windows RT never have I been presented with a choice of what audio types would go to Bluetooth which would go to other speaker. but that being said I have not owned or used blackberry or android

All I can tell you is that it's been fairly recent for me.  I've had the same Bluetooth headset for over a year and the same iPhone for almost 2 years.  I frequently used Google Maps while talking on my phone.  Until fairly recently the Google Maps audio would come through the phone while my phone calls would go through my Bluetooth.  I would turn the Google Maps volume down so I could still hear it in the background, but wouldn't annoy me while talking on my Bluetooth.  For some reason in the past couple months or so, all the audio started going through my Bluetooth. 

Google Maps does have an option to turn off the voice over Bluetooth.  However, even with that set to off, as soon as a call comes through (or a call is made) the Google Maps audio switches to the Bluetooth as well.  The only option, it seems, is to mute Google Maps entirely, which isn't a great choice. 

I guess I just find it more surprising than anything that iPhone doesn't have as basic a function that would allow you to set up your Bluetooth output options.

have you suggested it ? using feedback http://www.apple.com/feedback/iphone.html

there is way too much question bound in unsudden as how things works for apple to be able to browse and find suggestions in the forums

Yeah, I made a recommendation.  But I'm sure they get so many that mine will never get looked at.  I confirmed that Android has this function.  My Palm Pre had it.  Not sure why Apple can't make it work.  It'll be a pain to switch from iOS to Android but it looks like that's my only option unless Apple can figure out how to do it by July. 

I think there's a tweak in Cydia that'll do it but you have to jailbreak and there's no jailbreak available for the latest iOS. 

Paid $2.99 for an A2DP blocker app but I'm not sure that'll work...will have to wait until I leave work to try it out.  Hopefully.