The K100 did a good job of pushing traffic noise into the background, though people said that they could hear my kids' frequent squeals in those instances when I wasn't talking. (I found it very handy to have the large mute button right there within easy reach.)

The FM-transmitter button lets you hear calls and streaming audio (such as GPS directions) through the car's stereo system. You press the FM button, and an FM transmit channel is announced. Then you manually tune your car's radio to that channel, and you're ready to handle calls and tunes through the car's speakers, enhancing the listening experience. If you need to search for an available channel, no problem: The K100 lets you hold down the FM button until another channel is offered. Note: Your phone needs to support Advanced Audio Distribution Profile, or A2DP, to take advantage of the K100's streaming audio feature. For more details, check out the .

I believe that the quality of calls--especially outgoing calls--over Bluetooth in-car speakerphones must improve by leaps and bounds before anyone can describe it as superb. In the meantime, the K100's audio quality is decent, and consistently so. Considering that and its snappy design, the K100 is a solid choice as a Bluetooth companion if you need to use your phone in the car.

For more advice on selecting the right Bluetooth product for you, see "."