If you listen and talk on the phone as you are getting out of the car, that won't work?
I hate head sets, as I seem to have irregular parts. Nothing stays in my ear comfortably and the clips that go over the ear wobble.
I was hoping if you went out of range it would default back to the phone and you could talk as you walk, but this leaves me with the impression that if I do this the call will disconnect. True? Bah!