I've looked into this because I wanted to add the backup camera to my truck and have it display on the REC radio. The only input to the back of the radio is a 3 pin female connector that is not used. It looks nothing like an RCA jack for video. The backup camera experts I have spoken to say that it's possible that this is the camera input, but it might be proprietary to the Chrysler backup camera. They also say that the REC radio used in other vehicles with the backup camera option might be slightly different and have an entirely different input for the camera even though it appears to be the same radio. I have almost given up on the sleeper backup camera and I'm considering an aftermarket unit.
I went so far as to call Alpine and their customer service was completely worthless unless I had quesitons about my navigation.
I also called the aftermarket Mopar guys and told them what I was trying to do - add the backup camera option to a truck that has the same radio but no backup camera option and the reply I got after holding for 10 minutes was "We don't have a backup camera option for your truck. It's only available for some Chrysler vehicles. " THANKS. If I did my job like that, I'd be fired in a day!
On another note, distinctly remember seeing a truck for sale on eBay that showed pics of his rear seat video system with a Lion King video playing. That video image was also being displayed on the front seat REC radio! Not sure how he did it and it was more than a month ago, so the auction isn't available any more. I think it could be done, it's just a matter of finding the right person that knows enough about this radio.