iPhone calls via Car Radio

Has anyone any positive experiences with any of the new Bluetooth devices that can allow the phone to play through a radio in a vehicle?

If you have one of these, can you tell me whether a ear device is required still or does it pick up (how well) voice from a remote microphone?

I believe the effectivenes depends on how quiet the interior of your car is.

Unfortunately I drive a Jeep Wrangler so the only hand free option for me is a headset, especially if I drive around with top down and the doors off

I got a new Phase Linear BT1611i that works with my gen 1 iPhone. Need to figure out how to tweak the settings on the mic but everything works so far. Comes with an iPod adapter that will play the music on my phone as well.

The only problem I've had is that when I turn the Bluetooth off on my phone I have to re-pair with the radio to get connectivity again.

Excellent experience with the iPhone and the MyGig system on my 2008 Dodge Charger Daytona. Bluetooth even auto loaded my contacts to the radio.

I have the Sync system in mine and an iPhone. Works great. No ear device. Have been told they can't tell I'm not speaking directly into the phone.

Took me awhile to get use to it. First few times I got a call, I'd answer the phone, and be sitting there holding it to my ear, only to realize I was listening through the radio. Works pretty slick with my iPod also.