Mine came with a similar unit to the way yours sounds. I didn't bother trying to add to it, there are too many items not compatible with Aussi systems. There are many good systems available for not too much money and you know what you get will work here. You also get up-to-date features such as bluetooth, usb input etc. I got a JVC AM/FM/CD with those features, plus remote control which is useful in the camper, for about $150.