Most cars these days come with Bluetooth, supporting both hands-free calls and audio streaming. For older cars, GoGroove's SmartMini Aux works as a relatively cheap means of adding these wireless features.

However, the car needs an auxiliary input or adapter for running audio to the stereo.

The SmartMini Aux, constructed of black plastic, looks like an ultramodern drawer pull. Its offset T shape includes a flared base fitted with a Velcro pad for mounting in a car. A long wire tipped with a 1/8-inch audio jack leads out of the base.

The business end, a short, curved bar, is tipped with a microphone. A single button on top works as the SmartMini Aux's sole control. Blue and red LEDs hidden in the button serve as mode indicators.

GoGroove SmartMini Aux — This 1/8-inch port at the end of the SmartMini Aux works for charging, not audio. Josh Miller/CNET

A 1/8-inch port in the opposite end from the microphone serves as a charging port. GoGroove includes a USB adapter cable for charging the device.

Stealth mounting
At only 2.5 inches long, the SmartMini Auxi mounts unobtrusively on a car's dashboard. As you will want to leave it in the car, it's best to mount it low so as not to tempt thieves. The base itself comes off, revealing a 1/8-inch plug, making it possible to forgo the extra wiring and put it directly into an appropriately placed auxiliary input.

If primarily being used for streaming audio, it can even be left completely out of sight in the glove box or console.

Unlike many Bluetooth speakerphones, the SmartMini Aux is only intended for in-car use, and so does not have its own speaker. It must be connected to a stereo or other external speaker to be useful.

As a hands-free phone system, the SmartMini Aux offers few features of its own. Its single control button activates a paired phone's voice command, such as Siri on the iPhone. That feature lets you place calls using a contact's name or request music by name, depending on which commands the paired phone supports.

Along with activating voice command, the control serves as the answer/hang up button. There is no internal voice command or phone book feature.