I had SMB make my amp switchable. I utilize the in-dash stereo as the surround. The amp and monitor are powered by the house batteries. I've found the stereo system actually sounds better with the amp off...way too much bass with it on for watching a video so having it switchable keeps me from draining the house system as fast. My larger monitor was stollen, so now I'm just using a 10" screen. I plan to go with a new 19" soon probably a Jensen model
which will also be powered by the house batteries. The seperator will protect the starting batteries and the Kenwood stereo doesn't pull enough for me to worry. It's the amps and monitor I worry about.