Tel-Aid came with a new car sale for a year, they needed your credit card The dealer usually activated it, because it needed a get acquaintance call. I did not renew and have not missed it. MB used Analog because it was more widely available, that has recently changed when the FCC approved the request by the systems operators to discontinue ANALOG in January of 08. They are converting those channels to GSM the world standard now. MB is offering a updated transmitter for $1,000 or $600 if you are a current subscriber, Canada is following the US descision