Not too long ago I had a few Bluetooth earpieces that I mainly used  while driving. I had a few Motorola ones like the H700, plus I have still been using the Plantronics Voyager that I reviewed some time ago that I really enjoy. However, my problem was often that I didn't have the earpiece on when I received a call when I was driving.  would have to fumble to find it in my car, maybe turn it on, fold it open, and then place it in my ear – all the while was I was trying to keep my eyes on the road.
The Gadgeteer , SuperTooth HD Voice In-Car Speakerphone review, SuperTooth HD Voice In-Car Speakerphone review