Summary: You get traffic updates with traffic re-routing on your GPS with this little add-on. But attaching the antenna is awkward -- it's long and the little suction cups used to help extend the wire are kind of weak. Furthermore, the GPS has to be powered externally in order to enable use of the GTM-12, making the antenna not quite a portable add-on. Also, I've found that it is quite tight in the USB connection, making it a less-than-quick attachment for a GPS that is intended to be very portable.

Summary: The hype about the 15 month free subscription is just that - hype. It was THREE months. I had to give Garmin a credit card number, which they promptly charged $60 to, to even get my subscription activated. My expiration date is 15 months away, so it's obvious that only 3 months were free. Would not have purchased if I had known this in advance.

Summary: Very good product. If you commute to work everyday and want to know what's the traffic conditions, this will help. Keep in mind, it works off the Clear Channel FM radio signal, only available in major metropolitan areas. If you live in a rural area this may not work.

Mounting: the reciever MUST have a connection to the vehicle's 12V source, without it, it will NOT work. The Garmin Nuvi must be plugged into the 12V and the GTM unit plugs into the mini-usb jack on the side of the Nuvi.

If you're using an aftermarket mount like the RAM mount, you'll need to plug the top portion of your factory mount into the RAM mount, but that's very easy.

All in all this was worth the $125, no more waiting for all the radio commercials to be over when you need traffic updates.

The receiver needs to be activated, plug it into the Nuvi and follow the instructions.