What is that service called, gofar99? My radio came with something similar, but it's not accurate and I've been looking to switch. I have a Garmin too and it doesn't provide real-time, detailed info about traffic and such. My radio screen is large and easy to see, but the service isn't great. I'd be willing to pay for something better.
I've tried to cancel Sirius in the past and have had the retention caller hang up on me more than once. They mailed me a letter giving me free service for like 6 months. Rinse and repeat when it's due again. I don't see how they make money.