2FAS.... Excellent decision.. You will love the radio. I have a DS14 and I did add the two switches and it's no problem. Just make sure the switches are for a "DS" system and don't forget to purchase the switch "Nuts" in matching color (flat Black).

After opening the back cover "remove" the battery connection and then gently tap out the plastic plugs covering the switch holes. Then install the switches make sure the ribbon cable supplied with the switch is in correct orientation (look at the other installed switches) then fasten the switch with the Nuts use a "switch nut tools" (sold by Esprit). Make sure everything is secure, plug the battery back in and place back cover.

The system will recognize the switches automatically...

Enjoy..