The Concertone didn't work in the trailer we purchased, and after much research I decided that it would simply be foolish to spend money to replace it with another equally unreliable, under performing Rv specific dvd/stereo.
I purchased a Pioneer double-DIN media ready car stereo and installed. I had to fabricate a new frame, and work some magic re-wiring it into the trailer. Now that it's complete (I also replaced the garbage interior speakers)I am very happy. It plays cd's, DVD's, has tuner, has Bluetooth, has a USB input (will play both music and movies from my IPhone or USB thumb drive), is satellite radio ready, and Pandora internet radio ready. It has a video output so i could connect it to the tv in the trailer, and has audio inputs, so if I hook up cable to the tv I can get the sound through the stereo. Car stereo's do not have A/B speakers selectors, so I simply use the fader to switch from inside and outside speakers.
the sound is simply fantastic, and the Pioneer quality is 100000% times better than any Concertone product made.
It took a little time and some patience to get it all sorted out and installed correctly, but it was well worth it. If I had to do it again, I wouldn't think twice.