A new navigation unit from Kenwood, the KNA-G510, accepts traffic data from both Clear Channel and XM, giving you advance warning about traffic obstructions on your daily commute. Unlike portable navigation units from Garmin and Magellan, the Kenwood KNA-G510 is designed to work with any of Kenwood's touch-screen-navigation-compatible head units. The KNA-G510 plugs into the unit, giving it navigation capability. The compact design makes is possible to install in a driver-accessible position, such as underneath the dashboard or in a glove box. And accessibility is important because it has an SD card slot for loading new maps. The unit comes with maps of the United States and Canada preloaded. Clear Channel traffic data is broadcast over an FM radio signal, while XM comes in through a satellite radio signal. Traffic data from both providers covers most metropolitan areas in the States but generally only freeways and major highways. The KNA-G510 is powered by Garmin navigation software.