A new Garmin app launched at CES lets Android users use their phone and data plan to add live services to compatible Garmin Nuvi GPS navigation devices.

The “Smartphone Link” app is available free in the Android Market, and works with any Bluetooth-enabled 2012 Garmin Nuvi model. Data is received by the phone and transmitted to the GPS device, for display on the navigator’s screen.

Free information includes access to product updates from Garmin, along with basic weather reporting. More useful data requires a subscription.

Live traffic updated every two minutes adds $20 per year. Area fuel prices are available for $10 per year, and enhanced weather with current and five-day forecasts for major cities in the United States and Canada, along with weather alerts costs $5 per year. Current images from traffic cameras adds $10 per year. Clearly, to be truly beneficial there are real costs to using this “free” application.

Garmin says the app provides users with an alternative to separate data plans for their GPS devices and that the larger screens on their navigators will make the information easier to see than a typical phone screen. But it remains to be seen how popular an a la carte plan will be with users, especially in an era of increasing complaints related to subscription fatigue.