I know someone who is the proud owner of one of these:
He rang me while sitting in the driver's set of his stationery van - using the Blue Ant dangling from this rear view mirror as intended.
I could hardly make out his words, the sound quality was just appalling. Extremely honky and with low volume - sounded to be on the verge of mid frequency feedback all the time.
He then moved the unit to the self belt anchor near his left ear, made SFA difference. It was so hard to discern what he was saying that I would not wish to continue the conversation for more than a minute or attempt converse in more than four word phrases.
The he started up the engine and moved off - conversation then became quite impossible.
The exaggerated gearbox noise sounded like the phone was being used in a hurricane and his voice kept disappearing altogether.
Latest technology - right ?
....... Phil