I don't use an adapter for my iPhone 6.
I just plug the white USB to iPhone lead into the USB socket in armrest and it charges & sits quite comfortably on the rubber mat inside the armrest.
It then plays music either via Bluetooth or via InControl app if you have installed and prefer that.
Calls etc. go via Bluetooth as soon as phone is in car.
Often, I don't bother to plug it in at all, especially if it doesn't need charging.
I've been very impressed with it so far...unlike the crapnav...but that's another story.
Tony If it ain't broken, fix it till it is.