I didn't know that mk1 had built-in radio, that's great. Don't understand why they took it out. I intend to use it indoors too and with mk2 I'd had to buy 2 radio units. Don't have a stereo in livingroom currently and i intend to buy a little amp and build a matching size box with extra car mount and power supply installed. Maybe i can even find an amp that has enough space to install everything in one box.