Methods and apparatus for determining an available FM frequency channel for interfacing with FM modulated output signals from a wireless device are described herein. A SPS receiver, such as a GPS receiver, can determine its position based on conventional techniques. The SPS receiver can determine one or more available FM channels over which audio output may be transmitted. The SPS receiver can use the determined position to access a local data base of available channels. Alternatively, the SPS receiver can use the determined position to access a local database of allocated channels in order to determine one or more available channels. The SPS receiver may display a prompt or message that indicates an FM channel over which output audio is modulated.