Comments about Motorola Motorola T505 Bluetooth In-Car Audio Stream Speakerphone and Digital FM Transmitter:

The best blue tooth product ever. Very clear, no distortion send and receive for autos with a built system. Clip on visor and pair the phone instantly. No will know your using a blue tooth, it's so clean. I pair it with multiple cell phones and have one in every car. Pairing is a breeze.
Receives signals way farther than advertised, I think well over 100 feet.
Battery charge lasts forever. Shuts off after 30 minutes if not connected, so I never worry about forgetting to turn it off.
I think it's a must have, loaded with very usable feathers, I use them all.
This is as good as any built in system I've heard to date.