IPhone 6 + Bluetooth + Audi Q5 = Not working

Question

It's pretty clear from the thousands? of posts that there's a serious issue with iPhone 6 (and plus) failing to work with previously ok bluetooth devices, especially cars.
My iPhone 5 with iOS 8 and 8.0.2 worked flawlessly with our Audi Q5 (2011).  iPhone 6 struggles to pair and even when it does, it won't accept calls or use the "handsfree" audio.
It also fails to work with my bluetooth headsets, so I can drive and talk on the phone at the same time.
I've tried;
1. Removing all bluetooth devices / pairings from the car.
2. Removed the previous attempts at pairing with the car (on the phone).
3. Reset my accounts.
4. Changed the name of both the car and phone.
Currently it's not possible to use my iPhone 6 (64gb) with our car, meaning any attempts to use a phone is dangerous.
I think I'll return the phone and go back to my old iPhone 5.

Answer 1

Hi Pedro,
Thanks for the reply, but none of these solutions work.  Let's walk though each of these.
To resolve the issue, you'll need to first sign in to iCloud and review your devices:
My first question is why?  Why on earth do I need to sign into iCloud so that my Car, which is not connected to the internet or iCloud and connect to my iPhone (which also may not be connected to the internet)?   This is ridiculous!
But I'll humor Apple for now and try (even though I've been through all of these steps).
Sign in to iCloud on your iOS devices.
On one of your devices, tap Settings > Bluetooth and look under My Devices. You'll see all devices that are connected to Bluetooth, but make sure that you see your Apple devices that are signed in to iCloud and are using iOS 8.
Sign out of your iCloud account from any devices that you don't want to use. To sign out of iCloud on an iOS device, tap Settings > iCloud > Sign Out.
Step 1.  Done
Step 2. "On one of your devices..."  Which device?  My iPhone 6?   Sure.   No problem.  "You'll see all devices that are connected to Bluetooth".   Which device?  My iPhone 6?  My Car?  This is part of the problem!  The connections don't work!  I see no devices.
Step 3. "Sign out of your iCloud account from any devices that you don't want to use."  Done.   Signed out of all of my iCloud accounts.   Makes no difference.
Then, remove any inactive devices from iCloud:
Sign in to iCloud.com.
Select Find My iPhone.
Select any devices that aren't active anymore.
Wait for Find My iPhone to stop trying to find the inactive device.
You should see the option to remove this device from your account. Select it to remove the device.
The only devices that are listed are those that I want to use.
After following the steps above, restart the device with the issue. Then try to use it with your Bluetooth accessory.
Done that.  I shutdown my iPhone and Car numerous times.  Doesn't make any difference.
When I do get the iPhone 6 and my Car to pair and sync (I have to set this up from scratch each and every day I've tried this), my car automatically thinks it's making a call as soon as it's "connected", to the last number I dialed.   However when I look at my iPhone it isn't making a call at all! 
What's worse is that the iPhone essentially puts the Audi MMI system into a corrupted state, so much that I can't "hang up" the call it's thinking the iPhone is making from my car.   The only option is to disable bluetooth in my car all together so that Audi MMI navigation / audio / radio / car management system works again!
Let me make this very clear, if I turn on and sync my iPhone 6 with my Audi Q5 over bluetooth, it essentially disables features of my car!