I too have many niggles with iP6.
Bluetooth connects OK, but when making a call, there is no monitor on the display to show call in progress/Connecting, so no idea if it is progressing. Does not sound ring tone in the car, occasionally - if the call is picked up, I simply get a voice saying "hello" as they have silence.
To makes things even worse, if a conversation is underway, quite simply the radio will kick in and mute all voice connection which again adds confusion as person on other end does not know call has muted.
In last few days, while driving, I now have a regular Beeping and message saying iphone6 connected - This is repeated many times during a journey so effectively the radio is dropping the link and re-connecting.
My garage say this is all down to Apple, not Mitsubishi - but effectively for me the car is not fit for purpose