I just picked up a Bluetooth/FM modulator dongle for $10 last week through a Kinja/Amazon sale. Plugs into the cig lighter, connects with my iPhone 7, has a mic and does a great job taking calls...I thought my $16 JETech headphone/FM modulator was great but this thing is killer. I should've bought 3.
http://deals.kinja.com/add-bluetooth-to-any-car-for-just-10-no-aux-jack-requ-1788578133
I got a 32GB iPhone 7 to replace my banged-up iPhone 5 through Sprint for $200 online. We are an Apple family, so my wife won't let me go off to a Samsung or other device (linked calendars, photo-sharing, group texts with CC&C guys...)
New HU's are trash. Dongles allow me to interface with factory equipment without cutting or rewiring ('07 Cadillac with an odd-size, '78 Lincoln with a functioning 2-knob factory 4-speaker system). People at CC&C are far more impressed with a functioning Bluetooth phone connection in an old Lincoln without a single wire to run, and I am too.