The cable that hooks to your Garmin 2720 so that you can hear it thru your speakers, is it still available and if so what is it called? They have discontinued this type so I didn't know if it is still available. How exactly does it work? I have the cable already mounted to the back of the radio in the flaring. I was planning on buying the 2820 but if you can purchase a cable for the 2720 then I will just buy it instead because it is cheaper.